The two-day Living Green Expo this weekend, the largest green expo in the state, included speakers and exhibits from University of Minnesota extension programs. Britt Carlson, Minnesota Pollution Control Agency workshop coordinator, said the weekendâÄôs workshops were a good way to disperse green information because the audience was able to interact with somebody with field experience. Carlson said the expo has consistently grown each year since it started in 2001. She said 25,000 attended last year, and the MPCA, which hosts the expo, believed there were more people this year. âÄúPeople that come here are really motivated, and what they need is specifics,âÄù Carlson said. âÄúThey want lots of details about where exactly to find information or how exactly to do something that they run into a challenge as theyâÄôve done their green building project.âÄù She said the most popular workshops covered at-home food-related topics, including canning and freezing. Jane Jewett, who works with the Minnesota Institute for Sustainable Agriculture , discussed canning and freezing fruit and vegetables with a full room. Jewett said canning and freezing are green options because doing this with locally grown foods can greatly reduce external costs of food production âÄî things like transportation âÄî by 90 percent. âÄúThe transportation is such a huge factor, the amount of money and petroleum fuel and time is spent to move food,âÄù Jewett said. âÄúFor me, getting it local and preserving it is the way to go.âÄù She encourages people to find farmersâÄô markets and to buy locally. Sara Heger Christopherson, extension engineer and educator for the Onsite Sewage Treatment program, covered sustainable wastewater treatment options, including septic tanks. She said the tanks are not feasible because of the lack of âÄúgreen space.âÄù âÄúThe biggest issue is where would you find enough green space to replenish the water. For a lot of the other towns that are more on the outer rings itâÄôs much more common,âÄù she said, citing Washington and Anoka counties as places where the tanks are more common. In her presentation, Christopherson said proper water use is important and installing low-flow fixtures is an easy way to conserve. The Bell Museum of Natural History had a booth for the fifth of eight years the expo has been in existence. Jennifer Menken said they were promoting their online calendar to reduce paper use. The expo included 64 workshops, up from 48 last year, Carlson said. There were 274 exhibitors this year, according to the expoâÄôs website. According to the website, the expo itself is a green event. The website says event organizers make a âÄúconcerted effort to reduce solid waste and the use of water and energy.âÄù They compost, encourage visitors to use public transportation, make signs from recyclable plastic and use recycled paper.