PACE provided permitting and design for a major trunk sewer line replacement project in Big Gulch. PACE replaced 9,400 LF of existing concrete sewer line with a new 18-inch and 24-inch welded HDPE sewer trunk. An additional 9,550 LF of welded HDPE pipe was installed to convey up to 150 cfs of excess stormwater flows from the stream to protect the creek channel and stop the creek’s erosive down-cutting.


Client Name

Mukilteo Water District


Mukilteo, WA


  • Sanitary Sewer Trunk Line Replacement
  • SSO Prevention
  • High Flow Stormwater Bypass Pipeline
  • 18- & 24-inch HDPE Pipe
  • Design & Permitting