Cleaning up: Fieldwork at a beloved Bellingham waterfront park

Have you ever taken a sunset stroll through Bellingham’s Boulevard Park? If so, you know firsthand why the community cherishes this waterfront park.

You may not have realized that the northern portion of the park is also the South State Street Manufactured Gas Plant cleanup site — so named for its industrial past.

This spring you’ll see environmental contractors collecting soil, groundwater, and sediment samples for testing to help inform cleanup of this area of the park.

How do you investigate a waterfront cleanup site that’s also a city park?

Aerial view of Boulevard Park from north showing grassy lower park and upper park next to South State Street

Boulevard Park and South State Street MGP site, before the 2017 interim action

Crews equipped with survey equipment, fluorescent dye, drilling machines, and other specialized testing tools are up to the challenge!

The City of Bellingham’s Parks and Recreation Department will also be sure to keep you informed on how to recreate safely at the park during this work. As needed, the city will fence off any work areas and display informational signs. You can view updates of park projects from their Boulevard Park webpage.

Since last summer, crews have been busy doing this type of fieldwork throughout Bellingham Bay. See our stories about our other waterfront cleanup sites: I & J Waterway, Whatcom Waterway, and Central Waterfront.

Where is this site in the cleanup process? And what happens next?

Follow the image link to read a text description of the cleanup steps.

Steps in Washington's formal cleanup process.

Early cleanup work completed in October 2017, called an Interim Action, stabilized contaminated soil along the shoreline and removed a failing dock. For the remaining areas of the site, we are now nearing the final steps of Washington’s formal cleanup process, guided by the Model Toxics Control Act (MTCA).

The planned fieldwork, called a pre-remedial design investigation, will provide additional information to complete engineering design of the final cleanup action.

The City of Bellingham and Puget Sound Energy (PSE) are conducting this fieldwork in accordance with an Agreed Order with Ecology.

Engineering design and permitting for cleanup will take about two years to complete, with construction work expected as early as 2023. The cleanup work will include a combination of removing structures, capping contaminated soil and sediment, enhancing the natural breakdown of groundwater contamination, protecting the shoreline, monitoring conditions, and restricting activities that could disturb capped areas.

What happened here?

Historic aerial shows gas storage on Bellingham bluff and rafts of logs floating in the bay.

Manufactured gas plant operations on hillside and log booms in Bellingham Bay, about 1955.

A manufactured gas plant operated on the upland portion of the site from the 1890s to the 1950s. The plant made home heating and cooking fuel (gas) from coal. Other potential sources of contamination include historic railroad and lumber mill operations.

The city and PSE are cleaning up contamination from these historical industrial uses.

What will I see happening on the Bellingham waterfront?

Investigating soil and groundwater

Three-meter high boring machine with pistons and a tank-like track

A direct-push drill rig.

The cleanup action for the upland area of the site is a layer of clean soil and vegetation (a “cap”). To help refine the cap thickness and footprint, crews will take 20 shallow hand auger soil samples across the upper park area (just downhill from South State Street). We already have enough information from previous soil testing to design the cap for the lower park area on the water. Crews will also complete a topographic survey of all the upland site areas.

To better design the groundwater contamination cleanup, crews will gather more information from under ground. A direct-push drill rig will be used to determine subsurface conditions and to collect groundwater samples along the bluff and railroad tracks. Four new groundwater monitoring wells will be installed using hollow-stem auger equipment (two uphill from the pocket beach and two along the western shoreline.) Crews will also conduct two site-wide groundwater monitoring events using 21 wells during the wet season (April - May) and again in the dry season (July – September).

Check out the figures in the pre-remedial design investigation for sampling location maps.

Investigating sediment

The cleanup action for the marine area also calls for a clean cap. Since this will be underwater on the seafloor of Bellingham Bay, the design and investigation looks different from the upland areas.

The cap not only needs to isolate contaminated sediment, but in certain areas of the site it may also need to treat contaminated groundwater before the groundwater discharges to Bellingham Bay. This depends in part on how fast groundwater travels.

Green fluorescent dye flooding from forest stream to near-shore water. People monitoring on shore.

Example of fluorescent dye testing.

To measure the speed of groundwater entering Bellingham Bay, crews will inject fluorescent tracer dye into the nearshore sediment. Contractors will then time how long the dye takes to resurface. (Curious about environmental safety? Scientists also use these dyes in drinking water testing.)

Crews will also sample nearshore intertidal sediment and porewater (water contained within the sediment) in 12 locations using hand-held coring and probing equipment. And yes, this could look as cool as it sounds! For this site, contractors will see the dye at the sediment surface (at low tide) and the picture to the right is just an example.

The tracer dying and the nearshore sampling will help inform the design of nearshore sediment capping.

To design the cap for sediment further from shore, crews will take 17 Power Grab and eight vibracore samples from marine research vessels. A Power Grab sampler collects or “grabs” shallow surface sediment, and a vibracore is a hollow tube that’s vibrated into the sediment to collect a continuous sediment sample across varying depths.

A contractor guiding a sample held in jawed scoop  back to a boat

Power Grab sediment testing.

To evaluate how the seafloor sediment has changed over time and best design the sediment cap, crews will map the seafloor using multibeam sonar scanners from a marine research vessel.

Investigating coastal marine processes

Model showing direction of waves in Bellingham Bay from the south to the north, most intense in the Southwest

Bellingham Bay wave model from Cornwall Avenue Landfill engineering design. The South State Street MGP site is on the waterfront at the bottom/center.

This waterfront cleanup will protect human health and the environment, even with marine forces constantly interacting with the site.

Engineers will also assess their design with other coastal concerns such as sea level rise, tides, storm surges, tsunamis, and local wind and wave conditions. They will build off what we’ve already learned from engineering other Bellingham Bay cleanups. They will also apply the most recent city and state guidelines and best available science to design a cleanup resilient to these marine forces.


Pre-remedial design investigation activities, including data evaluation and reporting, are expected to cost $700,000. The city and PSE are funding partners for the cleanup. The city is eligible for reimbursement of up to half of their cost from us through the state’s Remedial Action Grant Program, which helps pay for the cleanup of publicly-owned sites. The Legislature funds the grant program with revenues from a tax on hazardous substances

Cleaning up Bellingham Bay

The South State Street Manufactured Gas Plant site is one of 12 Bellingham Bay cleanup sites coordinated through the Bellingham Bay Demonstration Pilot. The pilot is a bay-wide multi-agency effort to clean up contaminated sediment, control sources of sediment contamination, and restore habitat, with consideration for land and water uses. In 2000, participants in this initiative developed the Bellingham Bay Comprehensive Strategy.