The once a decade process of sewer cleaning and viewing begins on Monday. The process may affect traffic around Bos Landen, Brooks Circle, and on Washington Street. After the cleaning, a camera will be put through the lines. Pella Public Works Director Denny Buyert says some of the sewer lines in Pella are nearly a century old, and putting a camera through the system allows them to identify maintenance issues on these old lines, as well as newer ones. The most common problem is tree roots growing into cracks in the lines.