Sequencing Batch Reactor Wastewater Treatment Plant & Collection System Improvements
Client—Port of Grays Harbor, Washington
Gibbs & Olson provided the planning and pipeline design for the new packaged Sequencing Batch Reactor (SBR) wastewater treatment plant manufactured by EarthTek Environmental at the Satsop Development Park.
Before the new package plant was installed, it was necessary to reduce infiltration and inflow entering the system. The collection system improvements involved upgrading 1,500 feet of 6 to 8 inch asbestos cement pipe to 8 inch HDPE utilizing the pipe bursting method. Additional improvements included replacing 2 existing manholes and installing 4 new manholes along the pipe route. A portion of the improvements included rerouting 250 feet of 8 inch HDPE pipe utilizing open cut excavation. These improvements were completed in 2013 at a cost of $200,000.
Once the collection system improvements were complete, we worked with the Port to develop a scope and schedule for issuing a request for proposal to procure the new package plant which will replace the existing plant. We are currently assisting the Port with construction phase services. The project includes the installation and startup of the 40,000 gallons per day (gpd) plant along with the site, mechanical, structural, and electrical work. Improvements also includes installation of: 1,200 feet of 6 to 8 inch HDPE and 1,450 feet of 8 inch PVC piping with associated manholes; 2,750 feet of HDPE forcemain (1,050 feet will be installed via horizontal directional drilling to accommodate a creek and road crossing); and 5,500 feet of dual 2 and 4 inch HPDE forcemain. The project was completed in April 2015 at a cost of $2 million.