Air quality can also be an issue when the carbon dioxide and other odour causing emissions produced during the fermentation process are not recaptured or cleaned before being exhausted. Minnesota's only urban ethanol plant, Gopher State Ethanol, has experienced strong neighborhood resistance to odor and noise pollution. Plants in Benson, Luverne, Little Falls, and Marshall, Minnesota have also received complaints of odour.
The Final Report Regarding Gopher State Ethanol details many of the concerns regarding air quality issues and ethanol plants in Minnesota.
The source of an ethanol plant's power, as well as the type of production process, will affect the level of greenhouse gas (GHG) emissions. Natural gas will be the primary energy source for Saskatchewan ethanol plants. However, if electricity is produced from coal fired power plants, this will create more atmospheric pollution than a plant capable of integrated power co-generation. Power is typically used for steam generation and drying down the distiller's grains if the plant is not integrated with a feedlot.