Performance Impact Assessment Research Articles

Science on Ice

Antarctica is the one continent on Earth where science reigns. However, changes are just beginning and all nations must face radical shifts in the way they do business in Antarctica. Environmental clean-up of McMurdo Station, U.S. operations run by the National Science Foundation, was initiated three years ago. However, more regulations are coming. Under the 1991 protocol, nations must perform impact assessments on any proposed activity, and if those actions might have lasting or significant effects on the environment, the nations proposing them must circulate assessment reports to other countries for approval. All forms of waste produced, with the exception of materials which can be incinerated and human wastes, must be shipped home. Nations must monitor the environmental impacts of their activities. While science is still king in Antarctica, it now must share attention with environmental concerns.

Contaminant impact assessment and the contaminating lifespan of landfills

Some of the factors to be considered in performing impact assessments for proposed municipal and non-hazardous waste landfill sites are discussed. These factors include the effect of the mass of contaminant, infiltration, and attenuation in the hydrogeologic system on the contaminating lifespan of a landfill. The potential impact of fracturing of the soil separating the landfill from an underlying aquifer is examined. The influences of a compacted clay liner and (or) a natural, intact clayey layer below the fractured soil are examined. The concept of developing "triggers" to initiate leachate control measures, and the associated potential impact on groundwater, is discussed in the context of the potential design life of the underdrain system in a landfill. Key words: environmental impact, contaminant migration, landfill, design, fractures, liners, groundwater, leachate collection.