(425) 391-8585

"Cornerstone is the best underground utilities contractor in town. I use them on all of my projects because I work on a lot of environmentally critical areas. I trust Cornerstone to deliver on my toughest jobs."

– Jon Riser

Past Projects Seattle

Cornerstone works on both commercial and residential excavation and sewer pipe line repair projects. Here are a few examples of projects we have done in the past.
Seattle Commercial and Residential Excavation