Sewer interceptor: Right decision then and now
- Alex Mcintyre
- Lake Oswego Review - Opinion
After reading and hearing opinions urging the Lake Oswego City Council to reconsider the in-lake interceptor sewer option, I wanted to remind the community about the process and criteria that brought this decision forward.
As background, I joined the city in March 2008 as city manager. I knew that the number one issue I would face as city manager would be the proper and effective management of this large project. While I was not a part of the city when the decision was made to choose the in-lake, gravity sewer replacement, I certainly did my homework before taking this assignment. I too, questioned what appeared to be a unique solution to a complex public works problem.
The factors behind the decision to replace the existing sewer at the bottom of the lake are clear - the present one is too small, too old, and seismically unsound. It appeared to me that the decision to replace the line was sound and responsible.
Planning for this project required careful thought, thorough consideration, and sensitivity to cost. In 2000, the city began engineering research and evaluation of replacement alternatives. These included interim options to defer ultimate replacement, gravity flow and pumping options. All were technically, financially, practically and publically vetted. Capital costs, operation and maintenance costs, financial risks, siting and easement acquisition risk, impacts of construction on the public, and risks and consequences of failure were evaluated for each option. This is a document that I carefully reviewed before accepting the position here.
In July 2007, after many meetings with neighborhood associations, public hearings, council study sessions, Lake Corporation conversations, civic group meetings and open houses, the in-lake, gravity flow, buoyant, pipeline was chosen. Why was it chosen over the option to pump flows to the treatment plant? The capital costs were fairly close, according to the engineer's estimates. What I discovered is that where the options differed, they differed greatly.
First, the operations and maintenance costs of keeping six, new, large pump stations running, added $20 million over the life of the system. Siting the pump stations would require several property owners to sacrifice space on their lots - some with above-ground structures. Pumping also introduced energy costs that the buoyant gravity option did not have.
Second, the in-lake option was preferred because of the lessened impact to the community. There are about 700 households on the lake, its bays and canals. This is a large number of people, many of whom will be reminded daily with the in-lake option that there is a construction project in their 'front yard.' With the pumping option, those 700 households would still be impacted, since the lake would still have to be drawn down, roads built and equipment mobilized, to collect the flows from three trunk lines at the west end of the lake. Also, hundreds more residents along the route of the additional four miles of upland sewer required would be inconvenienced, plus thousands of drivers per day as construction impacted travel.
Finally, the in-lake option was determined to be more environmentally friendly with a much smaller carbon footprint as a result of consuming fewer natural resources for construction, lower risk from seismic events and required less energy to operate.
The council and staff heard similar preferences from much of the public in its outreach efforts that preceded its decision. We will all feel the impacts of this project; some more than others. In the end, we will all benefit from cleaner water in our lake and river and an efficient and seismically sound sewer system for more than 25,000 system users for decades to come.
Finally, I fully appreciate the concerns expressed by community members. I also believe that the city council tackled this problem in the most serious and responsible manner to arrive at the right solution.
Alex McIntyre is the city manager of Lake Oswego.