Wednesday, November 7, 2012

Around the Sound: Work underway at the Rayonier Mill cleanup site

By Marian Abbett, Site Manager, Toxics Cleanup Program

Over the past few weeks, you may have noticed activity on the Rayonier Mill site. The City of Port Angeles (city) and Rayonier have begun work on the part of the city’s CSO project on the mill property.

About one mile of CSO pipeline trenches will be on the former mill property. Some soil and groundwater the city is finding on the former mill property is contaminated, so the city and Rayonier are following special practices to manage contaminated and potentially-contaminated materials when they are found.

To give you an idea of what’s going on behind the fences, here are some photos of the work:

1) The city is digging the pipeline trench you can see on the left side of this photo. The new CSO project pipes, which will go in the deepest area, are on the right.

On the far left you can also see a silt fence. The city is using it to control erosion around the work site. This silt fence surrounds an area identified as a wetland.

2) The city and Rayonier are over-excavating to remove visibly contaminated soil found during construction. In this photo you can see an area where the city found soil contaminated with total petroleum hydrocarbons (TPH).

The deep flat area is the pipeline trench. The area where soil has been dug away below and behind the pipeline trench is where the city found the TPH-contaminated soil.

The water in the hole is exposed groundwater, which will be pumped out and treated.

3) Contaminated and potentially contaminated groundwater is being treated on-site. It is pumped into a temporary storage tank (Baker tank). First, particles are allowed to settle out. Then the water passes through a sand filter that removes smaller particles. Then it goes through a carbon unit to remove organics. Finally, the water is discharged to the city’s wastewater treatment plant.

4) The city is placing visibly contaminated soil in roll-off bins. Rayonier is disposing of this soil at landfills or recycling facilities that can take these types of wastes.

5) Rayonier is temporarily keeping potentially contaminated soil in stockpiles on the property. Rayonier is dividing soils by where they are found and how likely it is they are contaminated. They will test the stockpiled soil before final disposal or management.

A special fabric liner and sand covers the ground under the stockpiles. Sandbags hold down the plastic sheeting covering the stockpiles. Rayonier is inspecting the stockpiles daily. Since the stockpiles will remain on the site until final cleanup, Rayonier intends to create a semi-permanent cover after CSO project construction.

6) The city has removed one of the old bridges across Ennis Creek. They are now building a new bridge to carry the pipeline. The new bridge will be 100 feet across to allow for future potential creek restoration.

This photo shows workers building pile caps, which are part of the foundation of the new 100-foot bridge.

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