Biogas can be used to generate energy from a wide variety of sources. Wastewater treatment sludge is an effective source of waste to be used for generation of biogas to make energy which can be used to heat homes and run businesses. This would help decrease the use of fossil fuel for energy, but also give access to clean water, as wastewater treatment plants re-introduce purified water back into rivers and streams. High levels of ammonia cause inhibition of biogas, especially when using fats, oils, and greases as a feed source. Using gas chromatography, and colorimetric assays, the effects of increasing amounts of ammonia on biogas production when fats, oils, and greases were present in the feedstock was examined. The ammonia sensitivity of sludge from the Corvallis and Gresham wastewater treatment plants were compared. The Corvallis sludge was more sensitive to ammonia changes than the Gresham sludge, which is speculated to be because of different microbial community composition due to different feed sources at the respective full-scale facilities.