What we've learned: extent of contamination

Most of the progress we've made on the Rayonier Mill cleanup has been behind the scenes, gathering the information we need to plan efficient and effective cleanup actions. We can only conduct long-lasting and effective cleanups when we understand which contaminants are present, where they are, and how concentrated they are. We also need to evaluate possible approaches to cleanup. Thoroughly answering these questions has been a big part of our work on the Rayonier Mill site.

You can find out about our work:

  • Defining the types and amounts of contamination in the study area.
  • Evaluating several cleanup options for soil, groundwater, and marine sediments in the study area.
  • Investigating the sources and concentrations of dioxin in soil near the former mill.
  • Estimating amounts of contaminants that are introduced to Port Angeles Harbor but don’t have a clear source.

Interim Action Report: Volumes I, II, and III

Rayonier Mill cleanup upland and marine study areas.

The study area for the Rayonier cleanup is the former mill property and the marine environment next to the former mill. It's divided into uplands and marine areas.

We held a comment period in 2019 for public review of the draft remedial investigation and feasibility study for the study area (Volumes I, II, and III). After the comment period we finalized the reports. 

Upland Data Summary (Volume I)

The upland portion of the Rayonier Mill Study Area is the 75-acre former mill site. The Upland Data Summary (Volume I), Plates, and Appendices describes the types and amounts of contamination in the upland area.

The amount and types of contamination vary across the Upland Study Area. Most of the contaminated hot spots were removed with partial cleanups in the 1990s and 2000s. Rayonier removed 30,000 tons of contaminated soil from the site. Remaining contamination was spotty and found across much of the upland area.

There are limited areas of low and high pH (acidity and alkalinity) in groundwater. This can cause some metals to move out of soil and into groundwater. Groundwater here is not a source of drinking water because it's close to the saltwater of the harbor. Contaminants in the groundwater can migrate to the marine waters and sediments.

Contaminants found in soils and groundwater in the Upland Study Area include:

People and wildlife visiting the upland can be exposed to contamination by accidentally eating contaminated soil.

Read a summary of the 2014 Rayonier Mill marine data report.

Marine Data Summary (Volume II)

The Marine Study Area is about 1,300 acres of marine environment next to the mill property. The Marine Data Summary (Volume II) describes the types and amounts of contaminants in sediments in this area. Many of the same contaminants found in upland soil are also in the sediment, including PAHs, metals, dioxins, PCBs, and wood waste. 

People can be exposed to contaminated sediment by direct skin contact or by accidentally eating it.  People and wildlife eating fish and clams that have accumulated contaminants in their tissues may be exposed to contaminants.

Cleanup Alternatives Evaluation (Volume III)

The Cleanup Alternatives Evaluation (Volume III) describes and compares several options for cleaning up soil, groundwater, and sediments in the study area. To evaluate these options, we consider how long each cleanup might take, what they cost, and how well each option could protect human health and the environment. 


Options for cleaning up contaminated soil include excavating soil and either hauling it away or consolidating the contaminated soil on-site. Options vary in the size of the area to be excavated. If contaminated soil is left on the property, then a cap will cover the contaminated soil.


Groundwater is not a source of drinking water, and the primary concern is to protect against contamination moving from the groundwater to marine waters and sediments. Cleanup options vary from treating groundwater at the shoreline to treating it throughout the upland. Treatments include injecting air into groundwater to increase the rate of breakdown of contaminants or using chemicals to treat groundwater. 


Cleanup options for marine sediment include dredging, using fill, and capping. Enhanced monitored natural recovery means placing a thin layer of clean sand on top of the sediment and the activity of animals living in the sediment mixes the sand and contaminated sediments. A cap is a mixture of sand, gravel, and other materials that isolates the contaminated sediment under the cap.

Port Angeles Harbor Sediment Study reports

Port Angeles Harbor is one of seven Puget Sound bays at the center of the Puget Sound Initiative. We used special funding from the Puget Sound Initiative to learn where sediment in the harbor was contaminated and to study the nature of that contamination.

After the sediment study, we looked further into the sources of sediment pollution and developed a strategy for cleaning up the harbor. You can read more about these studies on our harbor-wide projects page.

North Olympic Peninsula Regional Background Study

If we removed every contaminant in Port Angeles Harbor, then the regional background level of contaminants would likely re-contaminate the area. An update to the sediment management cleanup standards introduced the concept of background chemical concentration levels to help us set appropriate cleanups, taking account of the regional background. 

In 2016, we completed a study of the regional background levels of several contaminants found in Port Angeles Harbor. In combination with our understanding of the risk contaminants pose to human health and the environment, the results of the regional background study helped us decide cleanup levels. You can read more about the North Olympic Peninsula Regional Background Study on our harbor-wide projects page.

Off-Property Soil Dioxin Study

We studied soil in upland areas near the former mill to learn whether operations at the mill contributed to elevated dioxin levels and look for specific areas of concern. In 2011, we released a draft report on the study.

Learn more: