Minnesota ranks #2 in hog production and #1 in sugar beet production in the U.S., generating about 11 million tons of pig manure and over one million tons of sugar processing wastes annually. Presently there are not cost-effective methods available to deal with these waste streams other than land application, which usually results in nutrient runoff into ground and surface water resources.
Each year Minnesota municipal wastewater treatment plants generate large amounts of oily scum, concentrated liquid called centrate, and sludge. These waste streams are disposed of either in landfills or by burning or subjected to additional treatment. However, new technologies have shown potential to capture resource values from these waste products while lowering the treatment costs for these waste streams.
The Soudan Iron Mine near Ely, Minnesota is no longer an active mine and is now part of a state park, as well as the home to a state-of-the-art physics laboratory at the bottom of the mine. The mine has also been discovered to contain an extreme environment in the form of an ancient and very salty brine bubbling up from a half-mile below the Earth’s surface through holes drilled when the mine was active. Strange microorganisms – part of an ecosystem never before characterized by science – have been found living in the brine.
Waste streams often contain unutilized resources that if properly extracted or otherwise utilized could be used to provide additional sources of renewable energy or other benefits. Wastewater is one of the primary candidate waste streams because of its nutrient content and researchers have been developing technologies such as microbial fuel cells and algal-based biofuel production in order make use of these nutrients.
Septic tank systems aim to treat sewage generated by homes and facilities that do not have access to centralized wastewater treatment plants. Currently 25% of the U.S. population relies on these systems as their primary means of wastewater treatment. However, the treatment capabilities of these systems are limited and so byproducts can contribute to degradation of water resources and other environmental problems and the systems emit instead of collect powerful greenhouse gases such as methane.
Over the past several years six environmental learning centers located around the state - Audubon Center of the North Woods, Deep Portage Learning Center, Eagle Bluff Environmental Learning Center, Laurentian Environmental Learning Center, Long Lake Conservation Center and Wolf Ridge Environmental Learning Center – have been implementing demonstrations of energy conservation, energy efficiency, and renewable energy on their campuses for use as educational tools for the thousands of students and visitors that come to the centers each year.
Production agriculture’s dependence on fossil fuel energy carries significant economic and ecological risks. The energy consumed within livestock facilities alone is the equivalent consumption of several large cities, and agriculture currently contributes approximately 14% of the total greenhouse gas emissions in the state. As consumers increasingly demand low carbon footprint products, adoption of clean energy systems in crop and livestock production would position Minnesota’s agricultural sector with a competitive advantage.
Adoption of renewable energy technologies and energy conservation practices can contribute in a variety of ways to the environmental and economic health of rural Minnesota communities through costs savings and emissions reductions. Engaging and coaching students as the leaders in the process of implementing such practices provides the added benefit of increasing knowledge, teaching about potential career paths, and developing leadership experience.