Ethanol, biodiesel linked to water pollution
Biodiesel refineries release pollutants such as glycerin, which disrupts the microbial cleaning processes used in wastewater treatment, the report noted.Storage of ethanol is also a concern. “Ethanol is highly corrosive and there is potential for releases into the environment that could contaminate groundwater and surface water,” the GAO said.
The U.S. government is encouraging increased biofuel use to reduce dependence on imported oil, mandating that ethanol's share of vehicle fuel content grow to 15 billion gallons, or an estimated 10% of all fuel sold by 2015. Total use of biofuels could grow to as much as 20% by 2022 as mandates kick in for the use for “advanced” biofuels, including those made from algae, grasses and nonedible plant material.
The GAO warned that biofuels developed from corn, such as ethanol, have a particularly significant impact on water quality because corn requires heavy use of irrigated water, fertilizers and pesticides. Fertilizer runoff can lead to aquatic “dead zones,” sometimes even hundreds of miles from the farm, the report said.
Using perennial grasses rather than corn to produce biofuels would help limit water pollution, the report said. Such grasses require less water and fertilizer and help protect soil from erosion.
The full report can be viewed here.
Photo: E85 ethanol is a blend of 15% gasoline and 85% ethanol. Credit: Swanksalot via Flickr.com