Sorry it took so long to answer your question. Yes, sometimes we did that. The problem is in situations where the on-site safety policy is for no gas/diesel engines. I know that some of the defense contractor we worked for were not at all flexible on the issue. Once while running a gas drilling rig indoors we developed strong gasoline fumes. We were using flexible metal hoses that tend to leak a bit. The rotor on the distributor cracked, causing very incomplete combustion, hence the odor. Keep in mind that underground storage tanks are being phased out, at least the smaller ones. Too many leaks. They're usually replaced with double-walled above ground tanks now. Big tanks are still buried at gas stations, truck termnals, or other places were fire and space concerns override.