Definition of On-Site

We received our comments back and they questioned our on-site energy use. We have a co-generation unit that takes the methane gas from the landfill to produce energy. The reviewers questioned the fact that since the landfill is not within our LEED project boundary then the co-gen probably should not count towards what we consider "on-site" My question is just because the landfill is not included in our boundary can it really not be considered on-site? I understood the credit that as long as the "eligible system (our co-gen unit) produces electrical power or thermal energy for use on-site" (EBOM Manual, 206) then that should count towards as "on-site renewable energy" right? And to clarify the landfill and the co-gen are about 2 blocks away from the project building, and the co-gen only serves the project building. Any help would be great, thanks!