What environmental issue is associated with extracting oil shale?

• A. Expansion of compacted soils creating excess waste and possible ground collapse.
• B. Depletion of tar sands yields.
• C. No waste produced.
• D. It yields immediate clean energy with no emissions.

Answer: (A)

The main idea is that oil shale extraction creates a lot of surface disturbance and solid waste, leading to environmental problems. Mined shale leaves behind huge amounts of spent shale and waste rock that must be managed and stored, often on the surface for long periods. This waste can accumulate and alter soil structure, and the heavy piles plus excavation can increase the risk of ground instability or subsidence, sometimes described as ground collapse in vulnerable areas. So, the environmental issue centers on waste generation and the potential for physical changes to the land from mining and processing that waste.

The other statements don’t fit because tar sands depletion is a separate resource issue, oil shale extraction does produce substantial waste, and the process does not yield immediate clean energy with no emissions.