Sanitary Sewer Collection System Study
The Sanitary Sewer Collection System Study was completed in 2021 by Anderson Perry & Associates to review the status of the city’s wastewater pipe and pump systems. The report evaluates the need for maintenance, improvements, and replacements to create a plan to maintain the current system and reduce future costs created by compounded system failures.
The last study was completed in 1999, and the current study will be used as a guide for improvements over the next 20 years.
The original sewer system in Hermiston was installed in the 1950s with vitrified clay pipes and brick and mortar manholes. Concrete pipe and PVC were later added to the system, with ductile iron pipe installed in some areas.
A few facts about the Hermiston wastewater system:
- 77 miles of collection mains
- 37 collection basins in the city
- 9 pump stations
- 4-inch diameter lines in residential areas
- 6- to 36-inch diameter collection system pipes
- 2 trunklines care all flow to the recycled water treatment plant in northwest Hermiston
The study used a camera inspection on 64 pipe sections, viewing 15,220 feet of pipe to look for problem areas in need of rehabilitation or improvement. These areas were selected from the city’s “monthly bad lines” list compiled from areas with common service issues.
Problems found include sagging pipes, cracks, cavities, root intrusions, infiltration, and protruding laterals. Examples of these issues are found in the report.
The City Council is reviewing the report, the Comprehensive Plan, and Capital Improvement Plan to determine priority projects in the next five years.
You can view the full report at the link below or visit the Hermiston Projects page to learn more about infrastructure projects in the city.
