Natural gas, composed mostly of methane, is not directly toxic to plants. When a gas leak occurs it displaces the oxygen in the soil pore spaces. This can lead to the development of anaerobic conditions and eventually the production of hydrogen sulfide gas. Hydrogen sulfide inhibits root respiration and nutrient uptake causing root death and plant decline. Gas damaged plants will grow poorly and have sparse new growth.
- Plants in a limited area around a leaking pipe or a line exhibit poor growth or death.
- Gas leaks from pipelines may give an odor of gas in the air while gas from landfills may not give an indication of odor.
- Affected soil from a gas leak will have a characteristic blue-black color and rotten egg odor.
- Roots killed by gas will be blackened and necrotic.
- Gas leaks should be reported and can be detected with meters by gas company employees.