Anaerobic digestion

Hello,

Iam new to seattle. With suitable qualification, Iam looking for a job in engineering companies that build biogas plants (anaerobic digesters) and manage the produced gas for power/heat. Now my question is,
1. Are there similiar companies in Seattle ?
2. Here, do they have cattle/chicken/pig farms? If yes, how do they dispose the waste generated from the farms?

I would appreciate if someone provide me a list of those companies and farms

Thanks