An oil spill could have potentially disastrous effects on land. The damage is hard to measure and contain, since it can effect complex ecosystems and spread if introduced to underground water. If the spill is severe it may take the land years to recover, during which time it is toxic to most plants and animals.
The presence of oil could render otherwise fertile land unfit for plant life as it reduces the soil's ability to hold oxygen. Since oxygen is a key element of plant growth and photosynthesis, existing vegetation is prone to suffocation. New plant growth may prove to be difficult, depending on the severity of the contamination. The oil also saturates the ground and acts as a barrier, preventing water from being absorbed, further inhibiting plants from being nourished.
As the oil is being absorbed into the earth, it runs the risk of contaminating underground streams. Since groundwater may flow across a large area, the oil has the potential to spread across a wide geographic region beyond the confines of the original site of the spill. Oil may even come into contact with and contaminate human water supplies.
Organisms and Animals
Oil is toxic to many micro-organisms, bacteria and animals that live on and within the land. As it seeps into the ground and comes into contact with minerals, organisms and bacteria it could destroy or compromise these entities. An oil spill has the potential to destroy entire ecosystems, leaving the surrounding wildlife displaced.