The environmental threat posed by electronic trash (also known as "e-waste") to future generations is on the rise. The disposal of outmoded electrical and electronic devices, which often include hazardous substances like lead, mercury, cadmium, metallic elements, and other compounds, is becoming more difficult. Electronic trash is made up of these devices. Surface water and groundwater are particularly vulnerable to contamination from e-waste that comes from landfills. Acids and sludge from melting computer chips can cause soil to become acidic and contaminate groundwater if they are dumped on the ground. Thus, e-waste disposal poses a serious risk to the environment and to human health and hence becomes a difficult social and environmental problem.