This method is suitable for underground oil storage tanks and other material storages with off-wall or on-wall concrete lining, especially for underground storages which have severe leakage.

Based on changes in electric property of underground media and natural potential field caused by landfill leakage, an online electricity monitoring system is designed to detect the leakage.

The gas leakage from underground storage not only means loss of money but also means reduce of gas supply to market.