Duke’s helped a vibrant city in the Pacific Northwest meet the main objectives of its decree: reduce infiltration and inflow (I&I), as well as sanitary sewer overflows. The consent decree contains a number of work requirements to achieve those goals, including the annual rehabilitation of 2.6 miles of sewer main with associated manholes and lower laterals, pump station renovation, implementation of a private sewer lateral program, a rigorous cleaning and inspection program, and root control, among other requirements.
The city has been working with Duke’s since 2014 to remove roots from their mainlines, which consists of a total of 110,578 ft of pipe in its Root Control program. Pipe sizes ranging from 6 in. to 21 in., of which 86% are in the 6 in. to 8 in. range.
Duke’s applies RazoRooter® II, an herbicide-laden, thick foam with the consistency of heavy shaving cream. Our crew inserts a hose from manhole to manhole, and the entire system is treated as the foam compresses against pipe surfaces and penetrates cracks, joints, and connecting sewers. Roots are killed on contact inside and outside the pipe walls, decaying naturally and sloughing away, with regrowth delayed for two to three years. This does not harm trees or other above ground vegetation.