ANIMAL BURROWING ATTRIBUTES AFFECTING HAZARDOUS-WASTE MANAGEMENT

Animal burrowing is critical to the formation of soils and contributes to the interface between geological materials and organic life. It al so influences the management of hazardous materials at nuclear waste f acilities and elsewhere. For example, residues and waste products from the production of nuclear weapons are released onto the ground surfac e and within engineered burial structures. Soil bioturbation has expos ed radionuclides and other hazardous materials to wind and rain, there by risking inhalation and injury to humans and wildlife on and off sit e. Soil bioturbation can expand soil depths and spatial distributions of the source term of hazardous waste, potentially increasing chronic exposures to wildlife and humans over the long term. Ample evidence in dicates that some of the large quantities of hazardous materials aroun d the world have been released from soil repositories, where they have also contaminated and harmed biota. Key burrowing parameters influenc ing these outcomes include the catalog of resident species, and their abundance, typical burrow volumes (void space created by soil displace ment), burrow depth profiles, maximum depth of excavation, constituent s and structural qualities of excavated soil mounds, and proportion of the ground covered by excavated soil. Other important parameters incl ude rate of mound construction, depth of den chambers, and volume of b urrow backfill. Soil bioturbation compromised the integrity of some ha zardous waste management systems using soil, but the environmental imp act remains largely unknown. Designers and operators of waste manageme nt facilities, as well as risk assessors, need to understand how burro wing animals influence hazardous waste storage.