Today is the 30th anniversary of Earth Day and several groups plan to rally at a Des Moines park to celebrate. Matt Ewing is a spokesperson for the Iowa Earth Day Coalition. He says they will focus on cleaning up the state’s water and energy.After the rally, the group plans to march to the state capitol, where he says they will demand that politicians listen to their concerns and address them in an active manner.Ewing says things aren’t a lot different today than they were when Earth Day started 30 years ago.The event is scheduled to start at 11 am at Stewart Square Park in Des Moines.