Hi David,
This is a written response in regards to OERS Incident No: 2014-1980. |
We recently had a sanitary sewer over-flow on N. Molalla Ave. and Thunderbird St. The cause of the overflow was due to a blockage in the N Molalla mainline approximate 60-ft south of the Toliver Rd. intersection. They type of blockage was unknown, but assumed to be a FOG (fats-oils-grease) or other unknown.
The over-flow call was received mid-morning on Monday, and I dispatched out our Public Works Crew to assess the issue and clear any found blockage. The blockage was located by inventorying downstream manholes from the overflow site. Once located and assessed the city utilized our Vac truck to remove the blockage. After the line appeared to clear and draining, a crew member returned to the spill location to assess necessary treatment for the overflow.
It was discovered at that time a small flow had made its way into a storm sewer catch basin, however the overflow had been contained in the sump of the catch basin. The spillage was removed from the catch basin sump with the Vac truck on site after sanity sewer mainline on N. Molalla Ave. was verified as clear and fully drained. The overflow on the surface was treated and cleaned.
The city recently purchased a Vac truck in 2014 to clean all sanitary sewer lines on an annual maintenance schedule or as needed basis. This year’s annual system maintenance is planned for fall 2014 to help reduce mainline overflows and backups.
In addition, the City is currently in the process of mapping the entire sanitary sewer system to address I & I issues. The future plan is to incorporate smoke testing, install flow meters and TV mainlines to identify issues over the next three years and develop a plan for funding repairs and replacement of failed lines.
Please let me know if you have any questions or need additional information.
Jennifer Cline, P.E.
City of Molalla
Public Works Director
O: 503.829.6855 Ext. #218
F: 503.829.3676
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