A California man is heading to prison for a scam involving cow manure.

Prosecutors say 66-year-old Ray Brewer scammed investors by promising to build “anaerobic digesters” that would convert cow manure into green energy.

He raised nearly $9 million – but Brewer’s plan turned out to be a load of… well, you know.

This week, Brewer was sentenced to six years and nine months in federal prison.