Marge Evans, a longtime volunteer for the annual Sangamon River clean-up, talks about why keeping trash away from the river is so important. Valerie Wells DECATUR â Keeping the Sangamon River clean is an important part of the Macon County Conservation District's role, and each year on the Festival of Spring, volunteers fan out to pick up whatever trash they find, both large and small. âOne year, we found a motorcycle,â said volunteer Marge Evans, who has been attending the event since it began in 1993. âLots of tires are thrown in the river. All sorts of things. People think they don't want something, so they just throw it away, throw it out the window.â