PG&E is about to get some of its gas from the manure of tens of thousands of dairy cows in and near Stanislaus County. Aemetis Inc. held a gathering Friday, June 10, at a new plant in Keyes that will process methane piped in from 60 dairy farms in the area. The $380 million project will reduce climate-harming emissions for both PG&E and the farmers. The latter also will get modest payments from Aemetis, helpful in a business beset by tight profit margins. Aemetis contractors will employ several hundred people as the company builds out the system by 2025. And it will add about 10 permanent workers to the 75 already at the Keyes site, which has made ethanol from corn since 2011.