Project area updates

Project updates related to the ongoing construction in work areas 1 through 8 for the North Mercer Island/Enatai Sewer Upgrade Project.

General project updates and news are located on the project landing page.

Project area map

Area updates

Click the desired area to view recent updates:

Area 1. North Mercer Pump Station

Recent update:

Update: North Mercer Pump Station fire alarm testing as early as August 7 , August 2025

Area 1 past updates

Update: North Mercer Pump Station fire alarm testing as early as July 17, July 2025
Update: North Mercer Pump Station fire alarm testing as early as June 10, June 2025
North Mercer Pump Station fire alarm testing as early as February 10, February 2025
Crews have been busy upgrading the North Mercer Pump Station, June 2024
What to expect at the North Mercer Island Pump Station over the next few months, February 2024
Preparation activities for final repaving on residential streets will begin as early as August 28, August, 2023
Utility work and preparation for paving beginning as early as August 14, August, 2023
Expect construction activities near North Mercer Pump Station for the next month, June 2023
Work on temporary pump station continues; Temporary generator running the week of June 12, June 2023
Update: 24-hour closure at 78th Ave SE and SE 24th St intersection extended, March 2023
Pipe installation progresses to SE 24th St as early as March 1, February 2023
Construction continues on temporary pump station, January 2023
November 29 Neighborhood Meeting Canceled, November 29, 2022
Please join us on Tuesday, November 29, for a neighborhood meeting about the North Mercer Pump Station. November 22, 2022
Temporary pump station construction begins; Pipe installation on SE 22nd St continues, October 2022
Saturday work will ramp up across the project corridor, September 2022
Pipe installation on SE 22nd St is underway, September 2022
Upcoming construction activities at the North Mercer Pump Station, August 17, 2022
Sewer line construction beginning as early as July 14. Expect increased noise, vibrations, and some driveway access interruptions on SE 22nd St, 78th Ave SE, and SE 24th. July 8, 2022
Construction staging to begin at the North Mercer Pump Station starting next week, June 24, 2022
Schedule Update: Tree removal in Mercer Island begins soon, June 14, 2022
Schedule Update: Tree removal near North Mercer Pump Station starting in June, May 18, 2022
Surveying continues/utility locates beginning in May, May 4, 2022
North Mercer Pump Station pre-construction StoryMap - What you need to know as construction gets started, April 19, 2022

Area 2. North-central Mercer residential streets

Recent update:

Update: Final paving and restoration activities planned on SE 22nd St, SE 22nd Pl, 78th Ave SE, and SE 24th St postponed , August 2025

Area 2 past updates

Area 3. North Mercer Way between the Park and Ride and Island Crest Way

Recent update

Final paving and restoration activities planned on 81st Ave S.E. and on North Mercer Way between 81st Ave S.E. and Island Crest Way as early as July 1, June 2025

Area 3 past updates

Area 4. I-90 trail

Recent update

Sections of I-90 Trail between 84th Avenue Southeast and Southeast 35th Street expected to reopen by July 11, July 2025

Area 4 past updates

Paving planned for sections of I-90 Trail between 84th Avenue Southeast and Southeast 35th Street , June 2025
I-90 Trail between 84th Avenue Southeast and Shorewood Drive now open, May 2025
Update: Sections of I-90 Trail on North Mercer Island to close for repair work as early as March 20, March 2025
Update: Sections of I-90 Trail on North Mercer Island to close for repair work as early as March 17, March 2025
I-90 Trail paving between 84th Avenue Southeast and Shorewood Drive begins next week, September 2024
I-90 Trail paving planned for the end of August between 84th Avenue Southeast and Shorewood Drive, August 2024
Two-day closure on I-90 trail near Covenant Shores as early as May 30, May 2024
I-90 Trail Detour on Northeast Mercer Island, December 2023
Updated Pedestrian Detour Map available, September 2023
I-90 Trail closing between 84th Avenue Southeast and Shorewood Drive as early as Aug 14, August 11, 2023
Tree removal beginning along North Mercer Way and I-90 trail, August 8, 2023
I-90 trail closed between Southeast 26th Street and Shorewood Drive as early as July 10*, July 7, 2023
Temporary lane closure along North Mercer Way near Fortuna Drive as early as March 13, March 1, 2023
Landscape restoration begins on the I-90 Trail, February 17, 2023
Landscape restoration begins, October 14, 2022
Saturday work will ramp up across the project corridor, September 2022
Schedule Update: Tree removal in Mercer Island begins soon, June 14, 2022
Construction work on the I-90 trail will begin as early as June 8, June 2, 2022
Surveying continues/utility locates beginning in May, May 4, 2022
I-90 Trail pre-construction StoryMap - What you need to know as construction gets started, April 19, 2022

Area 5. 90 PL SE

Recent update

Paving on Shorewood Drive and lower section of 90th Place Southeast now planned for May 30, May 2024

Area 5 past updates

Paving on Shorewood Drive and lower section of 90th Place Southeast planned for May 28 and 29, May 2024
Final paving on 90th Place Southeast & 89th Place Southeast planned for May 7-9, April 2024
Guardrail installation at 90th Pl SE starts on March 4 for approximately three days, March 2024
SCHEDULE UPDATE: Paving now planned for October 5 and 6, October 2023
Join us this Thursday, September 28 at 4:30 pm to learn about paving activities on 90th Place Southeast, September 2023
Paving beginning on 90th Place Southeast, September 2023
Crews begin installing pipe on Shorewood Drive as early as May 19, May 2023
Pipe installation on 90th Place Southeast to be completed as early as mid-June, April 2023
Upcoming water service interruptions on 90th PL SE, February 17, 2023
Schedule update and work on 90th PL SE, October 28, 2022
Saturday work will ramp up across the project corridor, September 2022
Water and sewer line relocation starting on September 13, September 9, 2022
Expect construction crews and activity starting on 90th Place Southeast as early as July 18, July 14, 2022
Surveying continues/utility locates beginning in May, May 4, 2022
90th Place Southeast pre-construction StoryMap - What you need to know as construction gets started, April 19, 2022

Area 6. Northeast Mercer Island

Recent updates

Backfilling on 97th Avenue Southeast and Southeast 34th Street beginning as early as August 11, August 2025

Area 6 past updates

Paving work planned along Southeast 35th Street and at the intersection of North Mercer Way beginning as early as August 7, August 2025
Pipe relining work on 97th Avenue Southeast and Southeast 34th Street intersection beginning as early as August 4, July 2025
Utility work near intersection of 96th Ave SE and SE 35th St beginning as early as July 21, July 2025
Pipe relining preparation on 97th Ave S.E. at S.E. 34th St beginning as early as July 8, June 2025
Upgrades to Lift Station 11 at Fruitland Landing continue, May 2025
Retaining wall installation on S.E. 35th Pl as early as March 17, March 2025
Portions of I-90 Trail on North Mercer Island to close for repair work as early as March 10, March 2025
Maintenance hole work on 97th Ave SE beginning as early as February 3, January 2025
PSE electrical work at intersection of SE 35th Place and E Mercer Way on January 23, January 2025
Pipe work near Southeast 35th Place and East Mercer Way as early as January 6, January 2025
Temporary paving and air vent line installation completed at Southeast 35th Place and East Mercer Way, November 2024
Sewer shutoff near Fruitland Landing planned for October 23, October 2024
Air vent installation as early as October 7, October 2024
Utility potholing work on Southeast 36th Street by City Hall this week, September 2024
Paving on Southeast 35th Place as early as mid-September, August 2024
Overnight equipment removal at East Mercer Way onramp to I-90 Westbound July 18, 11 p.m. - 4 a.m., July 2024
Temporary Frontage Road closure planned for evening of July 7 through July 12 ,July 2024
Single lane traffic 96th Ave S.E. starting as early as June 10, June 2024
Single lane traffic near Fruitland Landing starting as early as May 28, May 2024
Mercer Island Boat Launch parking lot reopening in June, May 2024
Puget Sound Energy repairing gas line on Southeast 35th Place near East Mercer Way, May, 2024
Gas line repair underway on Southeast 35th Place near East Mercer Way, May, 2024
Single lane alternating traffic upcoming on Frontage Road, April 2024
Construction activities starting early April on 97th Avenue Southeast and at Fruitland Landing, March 2024
Phase 4 detour and trenchless pipe installation coming to Southeast 35th Place as early as April 1, March 2024
Overnight equipment offloading at East Mercer Way onramp to I-90 Westbound, March 2024
Join us for a neighborhood conversation on Thursday, March 14 at 4 p.m., March 2024
Shoreline restoration begins near the Mercer Island Boat Launch, March, 2024
Crews will be offloading equipment at the East Mercer Way onramp to I-90 Westbound on March 5, February 2024
Pipe installation and structural upgrades coming to 97th Avenue Southeast and Lift Station 11 at Fruitland Landing, February 2024
Frontage Road and Mercer Island Boat Launch closed for up to three Fridays and Saturdays as early as February 9, February 2024
Trenchless pipe installation off 97th Avenue Southeast starts as early as February 12, February 2024
Phase 1 detour starting on Southeast 35th Place as early as January 16, January 2024
Southeast 35th Street Neighborhood Conversation Event Summary, December 2023
Pipe installation scheduled to start Southeast 35th Place mid-December, December 2023
Pipe installation on Southeast 35th Place mid-December, December 2023
I-90 trail closing between North Mercer Way and Southeast 35th Place as early as October 23, October 2023
Tree removal and pipe installation in Northeast Mercer Island to begin as early as October 23, October 2023
Underwater pipe installation moves toward Mercer Island in October, September 2023
Underwater pipe installation continues in Lake Washington’s East Channel, August 2023
Work in Lake Washington’s East Channel will last through early 2024, June 2023
Utility location around Enatai Beach Park as early as June 5, June 2023
Construction work on the I-90 trail will begin as early as June 8, June 2023
Weekend overflow parking for the Mercer Island Boat Launch at City Hall, May 2023
Work begins at North Mercer Way and Southeast 35th Street as early as May 31, May 2023
Preparation activities beginning at the Mercer Island Boat Launch, May 2023
Work begins at North Mercer Way and SE 35th St as early as April 10, March 2023
Construction on Southeast 35th Place begins November 28th, November 2022
Please join us on Monday, November 7, for a neighborhood walk on SE 35th Place, October 2022
Upcoming construction activities: King County to begin in-water work in Lake Washington’s East Channel, October 2022
Construction equipment and material storage coming to South Parking Lot in Luther Burbank Park, September 2022
Schedule Update: I-90 trail work begins today with closures starting as early as June 17, June 2022
Construction work on the I-90 trail will begin as early as June 8, June 2022
Surveying continues/utility locates beginning in May, May 2022
Construction equipment and activity coming to Mercer Island Boat Launch, April 2022
Northeast Mercer Island pre-construction StoryMap - What you need to know as construction gets started, April 2022
Construction equipment and activity coming to empty lot near E Mercer Way and Frontage Rd, April 2022

Area 7. Enatai Beach Park

Recent update

Update: Environmental monitoring planned as early as July 30, July 2025

Area 7 past updates

Environmental monitoring planned as early as July 18, July 2025
Substrate monitoring planned in the East Channel, December 2024
Final paving activities on 108th Avenue Southeast near Southeast 34th Street planned for September 23 – 25, September 2024
Paving Activities on 108th Avenue Southeast near Southeast 34th Street through late September, August 2024
In water work along Enatai shoreline planned to start late July, July 2024
Electrical work on 108th Avenue Southeast near Enatai Beach Park as early as June 11, June 2024
Construction continues at Enatai Beach Park, May 2024
Single lane traffic near Enatai Beach Park as early as April 10, April 2024
Nighttime work in the East Channel begins as early as November 14, November 2023
Underwater pipe installation moves toward Mercer Island in October, September 2023
Construction in the public areas at Enatai Beach Park as early as September 11, September 2023
Work in the East Channel beginning at 6 a.m. starting Aug. 8, August 7, 2023
Underwater pipe installation continues in Lake Washington’s East Channel, August 2023
Work in Lake Washington’s East Channel will last through early 2024, June 2023
Updated Bike Detour Map available, February 2023
Enatai Siphon pipe installation is complete! December 19, 2022
Nightwork for the Enatai Siphon pipe installation begins December 16 at Enatai Beach Park, December 15, 2022
Enatai siphon pipe installation planned to begin as early as December 15th. This will require work around the clock. December 2, 2022
Extended work hours in Bellevue in preparation for Enatai siphon pipe installation. December 2022
Upcoming construction activities: King County to begin in-water work in Lake Washington’s East Channel, October 7, 2022
Crews continue to prepare for Horizontal Directional Drilling (HDD) at Enatai Beach Park and Sweyolocken Pump Station, September 12, 2022
Saturday work will ramp up across the project corridor, September 2022
Construction equipment and activity coming to Enatai Beach Park as early as July 1, June 17, 2022
Construction equipment and activity coming to the Sweyolocken Boat Launch in June, May 18, 2022
Surveying continues/utility locates beginning in May, May 4, 2022
Enatai Beach Park pre-construction StoryMap - What you need to know as construction gets started, April 19, 2022

Area 8. Mercer Slough

Recent update

Restoration activities near Sweyolocken Boat Launch planned to begin September 23, September 2024

Area 8 past updates

The Sweyolocken boat launch and Mercer Slough connector trail is now open for community use!, July 2024
The Mercer Slough connector trail is expected to reopen Spring 2024 with a temporary closure as early as June for repaving, February 2024
Enatai Siphon pipe installation is complete! December 19, 2023
Updated Bike Detour Map available, February 2023
Enatai siphon pipe installation planned to begin as early as December 15th. This will require work around the clock. December 2, 2022
Extended work hours in Bellevue in preparation for Enatai siphon pipe installation. December 2022
Construction on Southeast 35th Place begins November 28th, November 22, 2022
Construction on Southeast 35th Place beginning next week, October 28, 2022
Crews continue to prepare for Horizontal Directional Drilling (HDD) at Enatai Beach Park and Sweyolocken Pump Station, September 12, 2022
Saturday work will ramp up across the project corridor, September 2022
Construction update: Expect intermittent loud noises and/or vibrations. Hammering to begin near Sweyolocken Boat launch. August 18, 2022
Mercer Slough Bike Trail will be closed while crews work at Sweyolocken Boat Launch, June 10, 2022
Construction equipment and activity coming to the Sweyolocken Boat Launch in June, May 18, 2022
Surveying continues/utility locates beginning in May, May 4, 2022
Mercer Slough pre-construction StoryMap - What you need to know as construction gets started, April 19, 2022

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