Manhole Rehabilitation Project - 2022

Project Image
Map of manhole locations

This project consists of mobilization, construction traffic control and infiltration correction of 90 sanitary sewer manholes. A map of rehabilitation manholes with existing sanitary sewer manhole photos is available at this link.

This is the 2nd year of a 5-year project.  The overall focus of this project is to reduce inflow/infiltration (I/I) of groundwater into manholes located where the river contributes to groundwater getting inside the manholes.  The wastewater treatment & resource recovery facility (WWTRRF) provides biological treatment of sanitary sewer collection flows.  WWTRRF does not provide any treatment of groundwater entering the collection system, and groundwater contribution through the WWTRRF has to be pumped and impacts the overall biological treatment.

This project provides for measures to seal the contact points between the manhole base and the first, and in some cases the second barrel rings.  Imagine sections of 4-foot diameter pipe, turned on its side and stacked on top each other.  The contact points where the pipes are stacked will be sealed from this project work to keep groundwater from entering.  The project will focus on 90 manholes located downstream of the 92 manholes completed in 2021. 

This project is funded through the Sewer Fund and is budgeted under capital outlay.

Project Title:
2022 Manhole Rehabilitation Project
Estimated Construction Cost:
136,750.00
Actual Construction Cost:
108,715
Project Type:
Final Project Cost (Construction + Engineering):
TBD
Year Completed:
Why It's Needed
 This project will assist with reducing I/I that was identified as an issue in the 2015 Adopted Sewer Collection System Master Plan and 2019 WWTRRF Facility Plan.  It will provide benefit to lower pumping costs at the WWTRRF to move the groundwater within the facility and assist with the biological treatment process.  Reducing groundwater inflow/infiltration (I/I) also provides for more future capacity for biological treatment at the WWTRRF under the National Pollution Discharge Elimination System (NPDES) permit.

WWTRRF dry weather flow is about 2.2 million gallons per day.  Groundwater contribution begins when Umatilla River flow reaches about 1,500 cubic feet per second (CFS), which occurs during the late fall through early spring.  The river also typically has two flushing flow events, ranging from 4,000 CFS to 10,000 CFS.  The proposed project is focused on reducing groundwater contributions above 1,500 CFS. 
Address

Intersection of SE Alexander Place and 18th Street
Pendleton, OR 97801
United States

Project Status

Project Milestones

Project Milestones
Date
November 2022
Milestone Description

Bid awarded to Integrity Inspection Services, of Nampa, ID, for $108,715 

Address Geolocation