Environmental soil drilling and study get underway at Harborview Medical Center at the end of June

The next step in the transformation of the Harborview Medical Center campus will be heard and not seen. That squeaky buzzing sound comes courtesy of the geotechnical work that will take soil samples for study. The work will begin on June 30, and should be complete by the end of July, and occur between the hours of 8:00 a.m. and 5:00 p.m.

The drilling will create loud, intermittent sounds and vibrations, and periodically emit minor fuel or exhaust smells from the diesel engine powering the drill. Noise will range from 60 to 100 decibels. This range is as low as the background music in a grocery store or as loud as a motorcycle stopped at a stoplight.

Engineers from Haley & Aldrich will drill six holes, known as borings, in the ground on the west side of the Harborview campus. Through these borings, engineers will study the soil, ground density, and groundwater conditions on the site that will serve as the foundation for the new inpatient medical tower and loop road. The borings will extend approximately 40 to 180 feet, about the length of one to five full-sized school buses. The borings need to be this deep to get below the proposed foundation level of the new tower, which will be deeper than any other building on campus.

Engineers will use a large geotechnical drill rig with a mast height of about 32 feet. While drilling, engineers will hammer a small steel tube into the ground and collect soil samples every 5 to 10 feet. Engineers will send the samples to a laboratory for review and testing.

Once drilling is complete, engineers will install monitoring wells to measure groundwater levels, which fluctuate throughout the year.

Engineers will also begin potholing, or mapping utility lines in the area, on the western side of the Harborview Medical Center (HMC) campus on July 10, 2025. Potholing will support the subsequent drilling work that began on the HMC campus in June 2025. The mapping of utility lines will help identify best spaces to drill, and support infrastructure plans.

Pothole engineers will locate utility lines by using a vacuum and a water jet to “pothole” down.

Equipment will be loud, but roads and sidewalks will remain clear. Work is scheduled to occur between 8 a.m. and 9 a.m. on July 10, 2025.

Have questions or feedback?

Email HarborviewBondProject@KingCounty.gov with subject line – “Soil drilling inquiry” or by call 206-305-8070.

Note: Header image upscaled to improve visibility. Actual image is below.