Knoxville 7th graders will be learning about living in and preserving the ecosystem, siltation, and water testing Tuesday, among other environmental topics. Middle School science teacher Sara Finnegan tells KNIA/KRLS News that students will meet with Will Prather, president of the Red Rock Lake Association to discuss siltation in Lake Red Rock, and then will tour the city water and wastewater treatment facilities, and county landfill, among other stops. The South Central Iowa Solid Waste Agency is sponsoring the learning experience. Finnegan says anyone interested in helping the students at the water quality testing site should e-mail her at finnegans@knoxville.k12.ia.us.