BIOGAS POTENTIAL
Source: National Renewable Energy Laboratory (NREL).

The figures below correspond with the biogas potential map scale, and they are measured in tons of methane emissions per year, by state.

• 0 to 999 (Lowest Potential)
• 1,000 to 9,999
• 10,000 to 20,999
• 21,000 to 35,999
• 36,000 to 99,999
• 100,000 and over (Highest Potential)

Within each state map, each county is color-coded based on the following scale. The figures represent the total tons of methane emissions per year, by county.

• 0 to 250 (Lowest Potential)
• 251 to 500
• 501 to 1,000
• 1,001 to 1,500
• 1,501 to 2,000
• 2,001 and over (Highest Potential)

NREL's biogas potential was calculated by considering the following animal types: dairy cows, beef cows, hogs and pigs, sheep, chickens (layers and broilers) and turkey. The data on animal population by county was obtained from the 2002 USDA National Agricultural Statistics. All emissions were calculated by animal type and manure management system.

BIODIGESTER LOCATIONS
Source: United States Environmental Protection Agency's AgSTAR Program.

The accuracy of these data cannot be guaranteed by AgSTAR. The economic and environmental benefits of biodigesters suggest that new biodigestor projects are most effective at existing feedlot operations.