Underground Utility Contractor – Portland, Oregon To stand the test of time and continue to operate as needed, underground utilities need to be installed with precision only available by highly skilled underground utility contractors. Our services include: Storm & Sanitary Sewers, Culverts & Water Main installation & repair Manhole Rehabilitation Septic System installation & repair... Example of Manhole Rehabilitation Oxbow Construction specializes in the repair, coating, lining and rehabilitation of manholes, wet wells and other sewer, storm and water related structures. Rehabilitation is an environmentally and ecologically friendly approach to extending the life of deteriorating infrastructures. Our company is Epoxytec® and StrongSeal® applicator certified. We guarantee, warranty and stand behind our products and workmanship.