Pump Station & Forcemain Improvements

Client—City of Longview, Washington

This sewer conveyance project was identified as a priority in the City’s sewer capacity report completed by Gibbs & Olson. The initial modeling work and the sewer capacity report evaluated and prioritized 46 pump stations within the City’s sewer system for possible future upgrades and recommends improvements.

Gibbs & Olson was hired to provide the surveying, design and limited construction phase services for this $6.5 million improvement project. The project included upgrading three existing lift stations, replacing an existing lift station on Hudson Street with a new pump station and a 20 inch 8,600 foot long HDPE forcemain. The new forcemain ties into an existing forcemain network that the City’s Mint Farm and Alabama Pump Stations discharge into. Adding a third pump station to this forcemain network required evaluation of complex hydraulics to ensure all three pump stations can convey their design capacities when necessary.