Tools > Cleanup > Snap Vertices (select from Main Menu)
Snap vertices to other nearest vertices or lines.
The Snap Vertices function moves any selected vertices to their nearest vertices or lines on indicated target layers.
•Note, the Maximum Snap Distance is the allowable distance a vertex may be snapped (to another vertex or to an edge).
•Vertices that are closer to one another than the Vertex Identity Distance, will be merged into one vertex.