In 2022, the Cincinnati Zoo & Botanical Garden’s Sustainability team, led by Stephenie Ritchey and Mallory Geresy, was awarded a Recycle Ohio EPA grant to acquire equipment for our award-winning Horticulture team. The Cincinnati Zoo’s Green Waste Recycling Program (GWRP) was put in place as part of our Zero-Waste initiatives, to process horticultural waste and debris into value-add mulching products to be used in our gardens and community projects.
The purpose of this award was to further the GWRP and supply the Horticulture team with a towable Bandit Model 1425 Mini Beast horizontal grinder. This machine reduces green waste volume by 75% or more by processing bamboo stalks, elephant grass, tree branches, logs, herbaceous waste, woody waste, pallets, etc. This creates a readily useable product, keeps used space at a minimum, eliminates the need to haul green waste (reducing emissions and transportation costs), and can help reduce irrigation needs by offsetting some of our annual mulch purchases.
Annually, we produce about 1,080 cubic yards of green waste, accounting for about 25% of our total waste volume. Historically, we’ve managed this waste through large, on-site mulching piles or, in special cases, through third-party hauling to off-site mulching facilities. However, with the development of new animal habitats, we no longer have the space for large on-site piles.
The Cincinnati Zoo piloted the Mini Beast in the spring of 2022, and it proved to be successful at processing nearly all the waste that we trialed as input, including bamboo stalks, elephant grass, tree branches, logs, herbaceous waste, woody waste, pallets, etc. We processed about 60 cubic yards of waste in roughly 4 hours. We observed a volume reduction rate of about 75%. With the use of the 2”-round screen, we were able to produce a mulch much finer than our purchased mulch. We were very pleased with the performance and versatility of the Mini Beast and finalized its keystone role in the GWRP!