Methane?
Manure pit
Typically, the mixture is composed of about 60 percent methane and 40 percent carbon dioxide regardless of the type of waste. Pure methane has heat value of about 1,000 Btu per cubic foot, so we can expect the methane-carbon dioxide mixture to have a heat value of about 600 Btu per cubic foot.
There have been many attempts to take advantage of cow manure using anaerobic digestion to produce methane. At small scale it can be done sort of economically but at industrial scale it's a nightmare.
The best thing IMHO is to haul liquefied manure in tankers to spread on fields as a terrific fertilizer. I'll bet there are a lot of happy cotton farmers with irrigated fields in that county. Bigger yields and faster growing.
There might have been a dairy methane digester responsible for this. Time will tell.