The Problem Over the last 5 decades, 546,000,000 gallons of oil has been spilled without any cleanup. The height of a crayon: A 3 inch layer of oil, the height of a crayon, covers the drinking water. In some places, the oil has seeped 5 meters underground. 40 years: In the Niger Delta, the average life expectancy is 40 years. For the rest of Nigeria, it is 55 years. In America, the life expectancy is 80 years. 1 in 8: In the Niger Delta, 1 in 8 people are at risk of dying of cancer. In America, 3 in 10,000 are at risk.