Tree roots in the sewer line is a common problem in New Jersey.
This is a cool visual showing how tree roots can grow and break into a sewer line causing a clogged sewer line and require NJ sewer cleaning and then NJ sewer line replacement or NJ sewer line repair.
Sewer line repair is often not possible when the root has damaged the sewer line pipe so you have to replace a portion of the sewer line.
The tree roots can grow into the sewer line pipe, the sewer cleaning will usually clear them out and ease the clogged drain but if the sewer pipe was damaged then sewer line repair or replacement is immediately necessary.
Another plumbing problem is that sewer cleaning may clear the tree roots growing in the sewer line but after some time the tree roots may start to grow again in the sewer line and clog the sewer line again so in that case sewer line replacement and protection may be the best option.