Portage Bay 138 Gate Retrofit & Pump Station 20 Improvement Project

Project Description

Improving Service Reliability in Your Neighborhood
Portage Bay 138 is a combined sewer basin, where combined sewage and stormwater flows to Pump Station 20 at the street end of E Shelby St and is pumped to a treatment plant.

During heavy rain events, high volumes of stormwater can overwhelm the sewer system causing a combined sewage overflow (CSO) into Portage Bay. The combined mixture of raw sewage and polluted stormwater can be harmful to humans, aquatic life, and other wildlife.
 
For this project, Seattle Public Utilities (SPU) will be modernizing the way our existing infrastructure manages high flows during rainstorms. To accomplish this, SPU will remove the existing flow restriction device attached to the buried storage tanks beneath the northern sidewalk on E Shelby St and replace it with an automated gate. This will allow SPU to optimally manage flows in the storage tanks in real time.
 
SPU is also making improvements to Pump Station 20, which is also located at the street end of E Shelby St, to help us continue to provide reliable sewer services to the community.
 
Because of the proximity of the work on Pump Station 20 to the Portage Bay Gate Retrofit project and the above-ground impacts, SPU will perform this work at the same time. This will help reduce the duration of construction in the area and other construction impacts on the community as well as minimize restoration costs.

Location

Construction will take place at the street end of E Shelby Street (link to project area map).  

What & Why

Portage Bay 138 is a combined sewer basin, where combined sewage and stormwater flows to Pump Station 20 at the street end of E Shelby St and is pumped to a treatment plant.

During heavy rain events, high volumes of stormwater can overwhelm the sewer system causing a combined sewage overflow (CSO) into Portage Bay. The combined mixture of raw sewage and polluted stormwater can be harmful to humans, aquatic life, and other wildlife.

For this project, Seattle Public Utilities (SPU) will be modernizing the way our existing infrastructure manages high flows during rainstorms. To accomplish this, SPU will remove the existing flow restriction device attached to the buried storage tanks beneath the northern sidewalk on E Shelby St and replace it with an automated gate. This will allow SPU to optimally manage flows in the storage tanks in real time.

SPU is also making improvements to Pump Station 20, which is also located at the street end of E Shelby St, to help us continue to provide reliable sewer services to the community.

Because of the proximity of the work on Pump Station 20 to the Portage Bay Gate Retrofit project and the above-ground impacts, SPU will perform this work at the same time. This will help reduce the duration of construction in the area and other construction impacts on the community as well as minimize restoration costs.

What's Happening Now?

The Project Team completed design and is preparing for construction to start in early 2020. 

The Project Team is reaching out to nearby residents to share project updates and potential construction impacts. If you are scheduling any Homeowner's Association meetings for early 2020, please consider inviting us to participate and share updates on the project.

Additional information will be provided once we have a contractor onboard. In the meantime, please review the Project Fact Sheet and FAQs for more information.

Community Benefits

The Portage Bay 138 Gate Retrofit & Pump Station 20 Improvement Project will improve water quality and public health by reducing the number of CSOs into Portage Bay. This work will reduce the risk of pump station failure and maintain safe working conditions for SPU crews within the pump station, in addition to helping SPU comply with industry standards and regulations.

Anticipated Impacts

We understand that this project is highly impactful, and our team has been working hard to find solutions and ease the stress of construction.
Here is some updated information regarding construction impacts:

Q: What hours will I be able to get in and out of my driveway?
Outside of the 6+/- weeks closure on the north side of E Shelby St for the gate retrofit work and the pavement restoration near the end of construction, we will ensure that access to driveways is maintained from 4 p.m. to 8 a.m. on weekdays to allow for easy travel to/from work and school.

Q: Will I be able to unload things near the construction zone?
Yes, we have worked with SDOT to set up a 15-minute load/unload zone at the NE corner of Boyer Ave E and E Shelby St to allow residents to pick up and drop of items closer to their homes. In addition, we will have a crew member designated to help residents transport items to their homes during working hours. A wheelbarrow will also be provided by the contractor, for use in transporting items.

Q: How will emergency vehicles reach residents through the construction zone?
We have worked with the Seattle Fire Department for them to develop an emergency services plan for our construction. Emergency services will be able to reach residents during construction.

Q: How will trash be picked up during construction?
During construction, trash pick-up on E Shelby St and the southern Fuhrman Ave "alley" will be consolidated so that it is all picked up on Wednesdays. You will be able to bring your trash/compost/recycling to the same location as you do before collection day. Our contractor will work to accommodate pick up.

Q: How will mail be delivered during construction?
Pedestrian access will be maintained at all times during construction and we have contacted USPS to coordinate mail delivery during construction. Please note mailboxes may be temporarily relocated in an effort to avoid delivery disruptions.

Q: How will residents be notified about upcoming work?
There are multiple ways the project team will keep in touch with the community. We will be out in the neighborhood continuing to engage residents in-person prior to construction. We will also send project notifications and share updates via the project listserv and project website.

Community Engagement

If you're interested in learning more and finding out about upcoming community engagement events, please sign up to receive project email updates.

Schedule

If you are interested in receiving updates about the project schedule, please sign up for the project listserv.

Early 2019

  • Project design continues
  • Engagement with the community

Late 2019

  • Finalize project design
  • Continue to engage the community

Early 2020

  • Pre-construction activities
  • Construction work begins, and it is expected to take 7-9 months
  • Pre-construction community outreach

Late 2020

  • Construction scheduled for completion
  • Construction updates, as needed, via website and listserv

* Tentative schedule as of November 2019 assuming that there are no project delays due to permitting, weather, or other factors.

Background

In some areas of the City of Seattle, sewage and stormwater runoff are collected in the same pipes, known as combined sewers. During heavy storm events, sometimes the flow in these pipes exceeds the sewer system capacity. 

When this occurs, the system overflows at an outfall structure designed for this purpose. This is called a combined sewer overflow (CSO). There are currently 84 outfalls in the City of Seattle where CSOs can occur.
 
To comply with State and Federal requirements, SPU must limit the number of CSOs at each outfall around the city of Seattle to an average of no more than one per year based on a 20-year moving average.
 
Portage Bay's basin 138 currently exceeds this standard at almost twice the required limit. The goal of this project is to reduce the number of CSOs in order to protect the environment and public health.
Following this work, SPU will continue to monitor performance and identify if additional action is needed to limit CSOs to less than 1 per year on average.