Luther Burbank Park Sport Courts Renovation

On Tuesday, September 3, the City Council authorized a budget appropriation to remediate the failing subgrade and complete the Luther Burbank Park Sport Courts Renovation. (AB 6533)

FieldTurf, the City’s contractor, has resumed construction, starting with removing and disposing of the existing asphalt. After removing the asphalt, FieldTurf began excavating the subgrade under the consultation of AESI, the City's geotechnical consultant. AESI is monitoring excavation to ensure the contractor only removes as much weak material as necessary to reach stronger soils. Once excavation is complete, new material will be laid and compacted to create a stronger base for asphalt paving.

This project is back on track, and the courts are currently planned to reopen for play in October. View construction photos here.

Construction of the Luther Burbank Park Sport Courts Renovation remains suspended while the City works with the designer and contractor to finalize the scope of work to repair the failing subgrade prior to repaving the courts. The proposed change order is significant, so staff plan to return to City Council on September 3 to seek authorization and a budget appropriation to move forward with the work. Staff anticipate construction will resume by early September.

Details for joining the City Council meeting are available below.

The hybrid meeting will be live streamed on the City Council’s YouTube Channel beginning at 5pm.

Register to Speak: Individuals wishing to speak live during Appearances (public comment period) must register with the City Clerk at 206.275.7793 or cityclerk@mercerisland.gov before 4pm on September 3, 2024. Each speaker will be allowed three (3) minutes to speak. A timer will be visible to online speakers, City Council, and meeting participants.

Join by Telephone at 5pm: To listen to the meeting via telephone, please call 253.215.8782 and enter Webinar ID 878 1912 3930, Password 730224 when prompted.

Join by Internet at 5pm: To watch the meeting online via your computer, follow these steps:

1. Click this link (Webinar ID 8878 1912 3930; Password 730224)
2. If the Zoom app is not installed on your computer, you will be prompted to download it.
3. If prompted, enter Webinar ID 878 1912 3930, Password 730224.

Join In-Person at the Mercer Island Community & Event Center at 5pm: The meeting will take place in the Slater Room Council Chambers, 8236 SE 24th Street.

Based on the testing results from last week, it has been determined that the failing subgrade must be replaced before court paving can be completed. This additional work requires a change order for the construction contract and includes:

• Removing more of the old asphalt surface;
• Removing weak soils from the subgrade; and
• Building a stronger base with new material.

Preparations for paving the courts will resume after the base is repaired. While this project was ahead of schedule earlier this month, the construction pause and the scope of the subgrade remediation unfortunately delay completion. Staff now anticipate opening the courts by early October. User groups have been notified that the facility will not be available for play in August as originally planned.

Staff are still finalizing the change order with DA Hogan and FieldTurf. The new project timeline and regular updates will be posted on Let’s Talk once construction can restart.

While prepping the sport courts for the asphalt overlay last week, City staff and the contractor discovered that the subgrade, or soil that the existing pavement is built on, is failing in some areas. Construction has paused so Associated Earth Sciences Inc. (AESI) could perform subgrade testing and provide recommendations for remediation.

This week, AESI used a dynamic cone penetrometer, or DCP, to test soil strength in five areas on the courts. A DCP device consists of a steel rod, a hardened conical tip, and a standard weight hammer. During testing, the hammer is raised to the top of the rod and dropped to drive the rod into the ground. The DCP of the soil is recorded after each blow of the hammer and correlated to standard measures of soil strength. After identifying the DCP measurement, the consultant used a t-handle probe to confirm the depth to firm soils.

Once the soil test results and remediation recommendations are received, City staff, DA Hogan, and FieldTurf will evaluate the project design and adjust as needed to strengthen the subgrade.

Here’s a look at construction progress at the Luther Burbank sport courts since the last update.

• FieldTurf finished installing the trench drain system on the east side of the courts.
• The conduit running the south fence line and the electrical handholes were installed.
• A few extra sections of the existing surface were removed, and NW Asphalt patched the saw cuts with new asphalt.

Now staff and DA Hogan, the City’s architect for this project, are completing inspections to confirm the courts are ready for the asphalt overlay. This project remains on schedule; view construction photos here.

The contractor began installing the new trench drain system on the east side of the courts this week. After installation is complete, the courts will be cleaned and prepped for paving. That phase includes installing new asphalt in the sawcut areas, then overlaying the entire court area with new asphalt.

There will be no Let’s Talk update next week due to the Fourth of July holiday. The next update will be posted on Thursday, July 11.

This project remains on schedule; view construction photos here.

The construction site was quieter this week, but progress continues to renovate the sport courts at Luther Burbank Park. Keep reading for this week’s construction update.

Drainage Investigation

On Monday, staff from the City’s Parks Maintenance, Sewer, and CIP teams met on-site to investigate the condition of the existing stormwater infrastructure. The team used a push camera to inspect the pipes from three entry points and confirmed they are still in good condition. Next week, FieldTurf will begin installing the new ACO Sport trench drain system, which will connect to the existing pipes to improve stormwater drainage at the facility. FieldTurf will also install a new storm drain cleanout to make it easier for Parks Maintenance to service the pipes in the future.

Conduit Installation

Service Electrical, a subcontractor of FieldTurf, also finished installing electrical conduit around the perimeter and up the middle of the courts last week, and FieldTurf backfilled the trenches this week. Junction boxes and electrical handholes will be installed later during construction.

As a reminder, no other electrical work is planned during this construction phase. Stantec Engineering is still developing a full lighting design, and an update will be shared on Let’s Talk when the design is ready to present to City Council for additional direction.

Other Work This Week

Excavation of the hill is complete, and FieldTurf also continued removing sawcut asphalt and other construction debris.

This project remains on schedule; view construction photos here.

Work continues to renovate the sport courts at Luther Burbank Park. Curious about all that dirt? Keep reading for construction updates this week.

Excavation Progress

FieldTurf continued excavating the hill south of the sport courts and laid the rock-stabilized construction access road. The contractor anticipates completing this phase of excavation by the end of the week. More work on the hillside will occur later during construction, including softening the hill slope and restoring the grass.

Other Work This Week

Demolition on the courts also continued this week. FieldTurf removed the existing tennis net posts and concrete footings; these will be replaced with new pickleball net posts as part of this project. The contractor also started trenching for electrical conduit, which is scheduled to be installed next week.

This project remains on schedule; view construction photos here.

FieldTurf started excavating the hill south of the sport courts today. This work is necessary to create construction access for hauling out material and bringing in the asphalt paver/other equipment. This post provides more detail about the work happening this week.

Trees

A quaking aspen and a black locust are being removed during hill excavation. These trees would've been removed later as part of the City's tree management under the City's general tree permit; the black locust is a non-native, invasive species, and both trees have created maintenance issues for the sport courts and surrounding area. The City is permitted to remove these trees under Tree Permit 2401-081. Per the permit, the City must replace the removals with two new trees. Two 6' ball and burlap Engelmann Spruce have already been replanted in Luther Burbank Park in anticipation for this tree removal. This work was coordinated with Andrew Prince, the City’s Urban Forestry Project Manager.

Cultural Resources Monitoring

A cultural resources specialist from Aqua Terra Cultural Resource Consultants is on-site during hill excavation in the event of inadvertent discovery, or the unexpected finding of historic, prehistoric, or other resources/remains. The City does not anticipate finding anything during this excavation but wanted to be doubly cautious given the historic nature of the park and the proximity of the project site to the admin building.

Demolition and Removal

In addition to starting the hill excavation today, FieldTurf is removing sawcut sections of existing asphalt to accommodate the new trench drains and electrical conduit being installed as part of this capital project.

View construction photos here.

Progress has already been made since the Luther Burbank Park sport courts closed to the public on May 21. FieldTurf started site preparation and minor demolition this week, including:

• Installing construction fencing and environmental protection measures such as compost socks and temporary catch basins;
• Removing the chain link mesh from the south fence to prepare for paving access; and
• Saw cutting existing asphalt at the court perimeter. (These sections of asphalt will be removed to accommodate new trench drains and electrical conduit as part of this project.)

Once court demolition is complete, FieldTurf will move on to excavating the south hillside and building the construction access path.

View construction photos here.