Questions and Answers

from the June 19, 2000 Elliott West Kick-off Meeting

Below are questions that were asked at the Kick-Off Meeting for the west end of the project. If you have questions that aren’t answered here, e-mail them to e-mail, or call 206/269-0229 x13.

Also visit our frequently asked questions page for more information.

Question: Given the rise in the topography along the tunnel alignment, will you pump water from the east to the west part of the tunnel and the CSO Control Facility?

Answer: No, this is a gravity flow tunnel. The west end of the tunnel will be slightly lower than the east end. . The depth from the surface to the tunnel varies, as the ground surface changes above it. The tunnel itself is relatively flat.

Question: Will this tunnel be an obstacle to future rapid transit on Queen Anne?

Answer: No, the tunnel depth is such that it is unlikely that it would interfere with any future transportation tunnels.

Question: When you did the rainfall projections, did you take an average annual rainfall or look at trends?

Answer: The County looked at data over the past 18 years. Over this timeframe, there were some "drought" years, so these were not considered when looking at the operation of the system under typical rainfall conditions.

Question: Will there be a sewer smell to the air coming out of the tunnel due to gas/methane build-up?

Answer: The County has invested in an odor control system by which air coming from both the empty and the in-use tunnel will be discharged through state-of-the-art odor scrubbers at both the east and west tunnel portals. We are confident in the effectiveness of this system in treating odors. Similar odor control technology is in use in some of King County’s other new facilities, and it works well.

Question: What are the shallow tunnels used for?

Answer: There are several shallow tunnels going under the railroad tracks, carrying a variety of different systems. For example, one brings flows into the CSO Control Facility from the Denny Way Diversion Structure, others take flows from the Control Facility to the outfall in Myrtle Edwards Park. The shallowest tunnel discharges stored flows into the Elliott Bay Interceptor (which leads to the West Point plant) after storms.

Question: Will construction also begin in the South Lake Union area this summer?

Answer: No, not this summer. We do not yet have a construction schedule for the South Lake Union area; however, when we do, we will notify the community and schedule a kick-off meeting in that area.

Question: Are you anticipating any settlement issues with the tunneling?

Answer: Given that we are blessed in this area with dense and firm soils, and taking into account the depth of the tunnel, we are anticipating little or no ground movement resulting from it. We will, however, be monitoring the situation continually and carefully.

Question: What about groundwater? Will you have to dewater?

Answer: We anticipate groundwater along the length of the project and will use tunneling methods to handle it.

Question: I am concerned about traffic congestion on Elliott Avenue West – not only due to trucks entering and exiting the site, but also due to construction parking and staging.

Answer: At 545 Elliott Avenue West we have a large site on which to work. All construction staging and construction parking can take place on site. There will, of course, be trucks entering and exiting the site and flaggers may be used for those situations. However, only a minimal amount of work will take place in the roadway itself; and, any lane blockages are restricted to non-peak hours in addition to the other restrictions placed by the City of Seattle. King County has developed an extensive traffic plan which has been approved by the City.

Question: There are a lot of construction projects either underway or scheduled to start along the Elliott Avenue West corridor. Are you coordinating with these projects?

Answer: We have been communicating on a regular basis with both private and public projects underway on Elliott Avenue West such as Immunex and the Galer Street Flyover Project. It is essential that we don’t "step on each other’s toes" during construction activity. In addition, we have worked closely with the Department of Neighborhoods to help SEATRAN produce a comprehensive information sheet, available to the community, which outlines the various projects, their dates of activity, and a contact person to call with questions. We will continue this level of coordination and communication throughout the life of the construction project.

Question: Will the CSO construction impact the fishing pier in any way?

Answer: The only impact that the project will have on the fishing pier is that construction traffic will be using the same road as passenger vehicles using the parking lot closest to the pier.

Question: What are the hours of construction?

Answer: Normal construction hours are weekdays, 7:00 a.m. to 7:00 p.m., and 9:00 a.m. to 7:00 p.m. on weekends. Some work may extend beyond those hours. If so, we will provide advance notification to the neighbors whenever possible.

Question: Have you thought about drivers using Mercer Street to avoid construction traffic on Elliott Avenue West?

Answer: It is possible that some drivers may choose to use Mercer Street over Elliott. However, we have control only over the routes used by truck traffic for our project.

Question: What is the footprint of the building in relation to the entire site?

Answer: Approximately one-half of the entire property will be taken up by the CSO Control building and its accompanying driveways, parking area, and landscaped area. The entire property will be used for construction and staging. At the end of construction, the entire site will be regraded so that it is level with the street.

Question: There will be open space left over at the south end of the County’s property. Does the County have any plans to develop that space and could it be used as community space for a park, or tennis courts, basketball courts, etc?

Answer: At this time, the County has no plans for the southern portion of the CSO Control Facility site other than providing it with minimal landscaping and continuing to hold onto it as part of the CSO property available for use in the event that wastewater treatment or environmental requirements change in the future. We would like to see how the new facilities work before the remaining land is divided, sold, or put to alternative use.

Question: Is there any opportunity in this design for a pedestrian bridge across the railroad tracks and into the park?

Answer: King County has no plans for such a bridge as part of this project. However, please check with the Department of Parks and Recreation for a full discussion of this question.

Question: Are there plans for art as part of the CSO Project in the South Lake Union area?

Answer: The County’s 1% for Art allocated to the CSO Project is being used at the plaza area of the outfall site in Myrtle Edwards Park. However, as you may remember, the Denny Way CSO is a joint project with the City of Seattle. The City has a multi-agency team that has been working with the South Lake Union community and there are art/community amenities being discussed.

For more information, e-mail or call Yvonne Kraus, community outreach coordinator,
206-269-0229, ext. 12.

Yvonne Kraus
Norton-Arnold & Co.
1932 First Ave., Suite 510
Seattle, WA 98101
Fax: 206-269-0249

Updated: November 12, 2001