Sustainability Efforts at the Denver Zoo

LEED Platinum • Water Conservation • Alternative Transportation • Zero Waste • Local Food • Energy Conservation

Zero Waste

Here at Denver Zoo we are working towards becoming a zero waste facility by 2025! To achieve this difficult goal we have developed an extensive recycling program, a green purchasing policy and a waste to energy system which will all bring us closer to achieving a zero waste campus. Denver Zoo monitors waste generated through our everyday operations to devise ways to reduce our waste stream and promote recycling efforts to both zoo staff and visitors.

Housed in our new Toyota Elephant Passage exhibit will be our state-of-the-art waste to energy system that will chemically convert zoo waste in a high temperature, low oxygen process into a usable combustible gas, called syngas. We will convert 90 percent of zoo's waste stream into energy, resulting in a diversion of diverting approximately 1.5 million pounds annually from the landfill, saving the zoo as much as $150,000 a year in energy and waste hauling costs. This system will meet the most stringent emissions standards and will produce one bi-product: ash, which can be used as a soil amendment. The electricity created by the system will be used to operate motors and pumps needed in the new exhibit, as well as other zoo energy needs (estimated at 20 percent). Operating at high temperatures will also produce waste heat that will be used to heat the 18,000 square foot elephant center and 11,000 square foot rhino/tapir holding facility, through radiant heat systems.

Our waste to energy efforts are furthered by Denver Zoo staff and visitors who help ensure the program is a success through waste sorting and reusing materials in innovative ways.

Before Denver Zoo transitions to waste equaling energy, we have been managing a systematic recycling program that touches on the many diverse recycling streams throughout the zoo. In 2011, Denver Zoo recycled over one hundred tons of materials ranging from metals and cardboard to electronics and cooking oil. To supplement our recycling and waste reduction programs, Denver Zoo has a successful composting program. In 2011, Denver Zoo composted over four hundred tons of animal and vegetation waste. Thanks to our participation in EPA's WasteWise program, we know that our recycling and composting efforts in 2011 saved over 500 million tons of carbon dioxide emissions.

In addition to managing all this waste, Denver Zoo has gone one step further and developed its own procurement database program. This program is designed to provide Denver Zoo a method to make sustainable and socially-responsible decisions for all of our purchases, including suppliers and manufacturers. Through exhaustive research of our local, regional and global procurement practices we are able to make informed decisions that help minimize our impacts on the environment, including carbon emissions. In addition to ensuring all purchases are as environmentally-friendly as possible, our software helps employees select products that will aid energy production in our new waste to energy system in Toyota Elephant Passage.

Download Zero Waste Flyer (pdf)