1. Are there any existing, out-of-the-box, easy-to-maintain, anaerobic biogas digester systems that can handle humanure that can be installed in an urban backyard?
2. If so, which one(s) are best recommended for a family of 4?
3. Plus, any recommendations for anyone to talk to within the San Francisco East Bay area about installation and making sure the system does not explode?
1. Non I'm aware of. It's always building / retrofitting
2. Family of 4 -> Puxin
3. Check https://solarcities.solutions -> they are biogas educators and might be able to help you.
today's feeble attempt to support the empire
100th Issue of Permaculture Magazine - now FREE for a while