Waterfront Mall Sewer Rehab
This successful project involved the rehabilitation of a 100 year old 90-inch diameter brick storm sewer beneath a new building under construction in a commercial area of Washington, DC located at K Street & 4th Street SW a little less than a mile southwest of the Capitol. The project overcame numerous challenges including tidal influenced backwater, limited site access and lay down area, lining around a short radius curve and confined space and storm inundation issues.The existing pipe was a 90" diameter, 800 foot long storm sewer. About half of the length of pipe is all brick, consisting of 3 layers. The other half of the length has the bottom part of the pipe constructed of brick (below the spring line) and the upper half is unreinforced concrete. The pipe makes one 90 degree short radius bend. The scope of work involved blocking tidal backwater from the Potomac River, bypass pumping, cleaning, lining and grouting. The liner was fed into the pipe through the manholes, pulled into position, and the panels were then spiral wound and connected using a Joiner Strip. The 3" annular space between the liner and host pipe was filled using high strength (6000 psi) cementitious grout. At completion the Danby spiral wound PVC profile renewal process created a rehabilitated storm sewer with all infiltration and exfiltration eliminated, increased chemical resistance, improved flow capacity and structural enhancement of the host pipe.