40 years ago I lived next to a 6 acre lake. It was so full of life, you bumped into frogs as you swam in it. It had Big bass, turtles with shells two feet round. We caught a bass two feet long.
Somehow a heating oil tank leaked a few thousand gallons into the stream that fed the lake.
After the oil spill, it was dead for years. Its shocking how complete it kills.
A couple of gallons of oil spill can contaminate ground water for miles around. We used to live in a rural area where people had underground tanks for heating oil and gasoline for their farm vehicles.
Leaks can be deadly dangerous. Any suggestion that this is a minor event is criminal.