The Environmental Protection Agency's AgStar program provides an online directory of on-farm biogas recovery systems. The directory lists equipment manufacturers and distributors; consultants, project developers, and other service providers; and financing and information sources.

The AgStar Web site,, provides many other resources, ranging from the basic information on digester systems to reports on specific digester designs, including some using dairy manure feedstocks. It also includes a database of funding sources. Those considering constructing a system can provide a basic site description via an online form as the basis for a follow-up discussion of project feasibility.

To download the directory, go to: