Lake Line Replacement Project
Work on the City of Mercer Island’s Sewer Lake Line Replacement Project, the largest capital project in the City’s history, will resume July 2.
This project will replace approximately 7,000 linear feet of sewer line located in Lake Washington along the northwest shoreline of the Island (known as Reach 3, extending from SE 32nd Street to Roanoke Way). The existing sewer line was installed in the mid-1950s, and is constructed of asbestos-cement (AC) material. It has been experiencing ongoing pipeline deterioration, capacity deficiencies and operation and maintenance problems.
The three main components of the project construction include replacement of the lake line sewer main and side sewers, relocation of Pump Station No. 4, and environmental mitigation.
Manson Construction and their subcontractors Frank Coluccio Company and Global Diving will continue to work to install side sewer connections to homes beginning July 2, 2010.
What's New
Sewer Line Work During Week June 21, 2010
During the week of June 21, 2010, dive crews will begin locating the connection points between each side sewer and the new mainline. If the valve is visible, divers will mark the location with a buoy. This non-invasive work will allow us to accelerate our dredging, which will begin July 2. It will also give you an example of the buoys we intend to use to mark pipes when we lay side sewer lines later this summer.
Safety is critically important. To protect divers, please keep boats at least 500 feet from all work areas. Also take the opportunity to become familiar with the buoys we will use later this summer to mark areas you should avoid.
Project Overview and Photos
This presentation provides a good overview of the project along with numerous photos. It identifies the project elements and notes some of the many challenges contractors face. It also provides information about the new Pump Station.
We Need to Hear From You
If you have an invisible dog fence, please let City officials know its location by calling (206) 275-7813. We don’t want to disturb your fence during construction, but we cannot accomplish this if we don’t know where it is. In addition, let us know if there is anything else underwater beyond the end of your dock that might tangle dredging equipment, such as boat anchors, irrigation lines or any other lines.
Construction Equipment
Construction requires mobilization of several pieces of large equipment, including dredges, derrick barges, floats and tugs. This presentation shows you the equipment that is being used for the lake line construction.
Park Closures
Manson Construction is using SE 32nd/Proctor Landing for construction staging. Therefore, the Proctor Landing park site will be closed to public use for the duration of the project. The area under I-90 is also closed through 2010.
There are several other parks and street ends which residents may use along 60th Avenue SE, including:
- Garfield Landing – SE 30th and 60th Avenue SE
- Slater Park – SE 29th and 60th Avenue SE
- Calkins Landing – SE 28th and 60th Avenue SE
All three areas are open and available for people to use during the summer. The City regrets any inconvenience for closures at Proctor Landing and I-90, but we need to provide a safe and secure site for construction activities.
Project Updates
Learn more and follow our progress with the lake line construction.
June 2010
April 2010
January 2010
August 2009
June 2009
May 2009
March 2009
Environmental Review Document
The City has prepared an Environmental Review Document (EID), which evaluates the impacts of the proposed project on the human and natural environment. The Environmental Protection Agency (EPA) has determined that the proposed project does not meet the criteria for preparing an Environmental Impact Statement under 40 CFR Part 6.207. EPA has prepared a preliminary Finding of No Significant Impact (FONSI) for the proposed project. To review the report, click here.
(Published in the Mercer Island Reporter April 29, 2009)
