We wonder why the Denver Zoo is launching what appears to be their own waste management plan separate from the city of Denver. The City’s Master Plan for Managing Solid Waste in the Mile High City, when considered alongside the Zoo’s proposal to utilize Other Than Solid Waste Incinerator/Gasification-Pyrolysis to “manage” its waste, raises questions as to Denver’s overall management of its solid waste. Solid waste is defined as “garbage, refuse, sludge from a waste treatment plant, water supply treatment plant, air pollution control facility, or other discarded material; including solid, liquid, semisolid, or contained gaseous material resulting from industrial operations, commercial operations or community activities” (6 CCR 1007-2 Part 1). Denver also encourages composting to keep trash out of landfills.
The Denver Zoo’s EDOP, which details the proposed project, lists the waste stream categories as a “mixture of biomass and operations waste, material that can be beneficially processed into a viable solid fuel and has an energy value, paper/cardboard, urban forest residue from Denver Parks and Recreation” (p. 16-17). Biomass and operations waste and urban forest residue are not defined, and there is no discussion in the EDOP of analyzing “urban forest residue” for pesticides, herbicides, and nitrates before it is “pyrolyzed,” converted into pellets and syngas. Paper and cardboard, often bleached and containing formaldehyde based glues, are also not discussed in the EDOP in terms of testing.