Answers to Frequently Asked Questions about HeronPark’s Plan to Reclaim Ross Island

“Non-hazardous” means the sediments do not meet the definition of hazardous waste under the U.S. Environmental Protection Agency standards used for the Portland Harbor Superfund Site (PHSS). In general, that means the material would not need to be disposed of in a hazardous waste landfill, which is a specially permitted facility designed to accept hazardous materials.

Before any sediments are accepted, HeronPark will review the laboratory test results and supporting information for the material. For some areas of the PHSS, this review may involve several thousand individual prior test results. That review will determine whether the sediments meet the Ross Island facility’s acceptance criteria.

The main contaminants of concern for the PHSS are typically polychlorinated biphenyls, or PCBs, and certain metals. These contaminants attach to fine sediment particles and do not move easily through water. If sediments are accepted, HeronPark would place them in an engineered area in the existing deep pit under the Ross Island lagoon and cover them with an engineered cap of clean material to isolate the sediments and prevent exposure to aquatic life.

HeronPark will not accept sediments with more mobile contaminants, such as liquid petroleum hydrocarbons, even if they are classified as non-hazardous. Acceptance would depend on the test results, the facility’s criteria, and whether the material is suitable for the intended use.

Prior to any implementation, the detailed acceptance criteria will be submitted in a formal permit application to the Oregon Department of State Lands and Department of Environmental Quality. This permit process will be transparent and open to public comment. Only sediments that meet the permitted criteria will be accepted.

HeronPark’s reclamation of Ross Island is anticipated to begin in July 2029 and extend to 2040 to 2042. This is based on the schedule for the Portland Harbor Superfund Site, which is determined by the U.S. Environmental Protection Agency (USEPA) and the potentially responsible parties (PRPs). Commitments from the PRPs for the volumes of sediments that will be placed in the Ross Island lagoon are expected to occur in 2026 and 2027. The reclamation plan will be designed to accommodate these volume commitments in 2027. The reclamation design, financial assurance plan and other details about the reclamation will be submitted to the Oregon Department of State Lands (DSL) as part of HeronPark’s application in 2027-2028.

The DSL evaluation of the permit application will involve a transparent public comment process. It is anticipated that the DSL permit will be issued, the financial assurance plan will commence, and the site will be prepared in the late 2028 – early 2029 timeframe to receive sediments in July 2029.

The regulatory review and permitting process will also include involvement of the Oregon Department of Environmental Quality, the Department of Fish and Wildlife, the State Marine Board, the City of Portland, the USEPA, the U.S. Army Corps of Engineers, the U.S. Department of Fish & Wildlife and NOAA's National Marine Fisheries Service.

There is a possibility that the schedule could move faster and the placement of sediments and the reclamation could begin in July 2028, but this would depend on the schedules of the USEPA, the PHSS PRPs and the regulatory and permitting process aligning better than expected.

Yes. Implementation of the reclamation plan and construction of the cap will require clean “Class A” fill. This will likely come from navigational dredging in the Willamette and/or Columbia Rivers. Sediment/fill from other environmental restoration projects may be considered for placement under the cap in accordance with the fill quality requirements that will be established in the new Department of State Lands permit.

HeronPark anticipates closing on its acquisition of Ross Island in the 2027-2028 timeframe in association with the Department of State Lands permit process. Until then, the R.B. Pamplin Corporation remains the owner of Ross Island and remains responsible for it.

The reclamation of Ross Island will be self-funded by user fees paid by the responsible parties for the Portland Harbor Superfund Site. No taxpayer funds will be required. Furthermore, the reclamation of Ross Island will save taxpayers money because the State of Oregon, the City of Portland and the Port of Portland are potentially responsible parties for the superfund site cleanup. Sending the sediments to Ross Island will be less expensive than alternative sites further away.

HeronPark is engaging with public agencies about commitments to accept ownership of the completed nature preserve. A formal commitment is anticipated prior to HeronPark submitting its formal permit application to the Department of State Lands (DSL) in 2027-2028, and possibly sooner. The post-closure care trust that will be part of the financial assurance plan in the DSL permit application will provide an endowment that will avoid the future nature preserve becoming a liability and burden on any accepting public agency.

HeronPark’s application for a Department of State Lands permit, expected in 2027-2028, will require a fully transparent public comment process. Additionally, HeronPark is engaging with community groups to listen to the community’s priorities for the reclamation and future of Ross Island. Updates will be provided via this website. Feedback from all interested members of the community will help shape the final plan.

Yes. HeronPark is reaching out to Tribal governments that have ancestral rights related to the Willamette River and/or are interested in the future of Ross Island along with members of the tribal community in the Portland metropolitan area. This consultation process will help guide the plan for reclaiming Ross Island and managing its future. 

Transporting and placing Portland Harbor Superfund Site sediments in Ross Island will reduce air emissions, especially harmful diesel particulate matter (DPM) emissions, by over 99% in comparison to transporting the sediments to alternative sites in Eastern Oregon. This is because: 1) Ross Island is approximately 1/20th of the distance; 2) the sediments will be transported to Ross Island by tugs/barges, which emit less than 1/10th of the emissions of trucks and/or rail transport per ton-mile; and 3) HeronPark intends to utilize tugboats that have special, high efficiency DPM filters, plus electric utility boats.

There are five confined aquatic disposal (CAD) cells in the Ross Island lagoon that were constructed between 1992 and 1998 to receive 160,000 cubic yards of contaminated sediments from the Port of Portland (the Port). They were constructed under permit from the Oregon Department of Environmental Quality (DEQ), the U.S. Environmental Protection Agency, and the U.S. Army Corps of Engineers. They have been extensively studied since 1999, and they are monitored on an annual basis.

CAD Cell #5 had a slope failure and breach between 1992 and 1998 caused by Ross Island Sand and Gravel Co. (RISG) mining sand and gravel too deep and too close to it. The CAD cells and the location of the breach of CAD Cell 5 are shown in the below figure.

Investigations by the Port and RISG under the direction of DEQ found that RISG had processed some of the breached material and mixed it with other sand and gravel on Hardtack Island. The investigations also found that other sediments in the southern part of the lagoon contained unacceptable concentrations of various contaminants.

A November 2000 Site Investigation Report by HartCrowser for the Port evaluated the potential for groundwater transport of the contaminants in the CAD cells. HartCrowser’s extensive field testing and hydrogeologic analysis determined that “groundwater flow is upward toward the lagoon, eliminating potential transport of contaminants to deeper groundwater and the Willamette River. The predicted concentrations of Port-related chemical constituents reaching surface sediments and surface waters or Ross Island Lagoon are below corresponding risk-based screening criteria and regional background levels.”

In 2005, DEQ issued a Record of Decision (ROD) requiring repair and capping of CAD Cell 5, the consolidation and upland confinement of the mixed material on Hardtack Island, and the construction of an extensive 3-foot-thick cap over parts of the southern portion of the lagoon. The cap mostly consists of fine clean sand. The below figure shows remedial action areas of the ROD.

RISG completed the work, and DEQ issued a No Further Action determination in 2011. The remedy and its cap have been monitored and maintained annually since 2012. Documentation of this work is publicly available from DEQ.

Lessons learned from the CAD cells and the remedial cap include:

1. The CAD cells have performed as designed to prevent the contaminated sediments in them from impacting the aquatic habitat, so long as they are not undermined by slope failure. The CAD cells have been in place for approximately 30 years, and the cap has been in place for over 15 years.

2. The 3-foot-thick cap in the southern part of the lagoon has performed as designed to prevent the contaminated sediments under it from impacting the aquatic habitat. Monitoring and maintenance have been performed by RISG since 2012. The maintenance has consisted of periodically adding additional capping material in small areas that show settlement.

3. The demonstrated success of the existing 3-foot-thick cap in protecting the aquatic habitat indicates that a similar cap could be successful over the envisioned placement of Portland Harbor Superfund Site (PHSS) sediments used to fill in the deep pit under the lagoon.

4. Groundwater transport of contaminated sediments in the CAD cells was determined to not be a threat to Ross Island Lagoon and the Willamette River. This has been confirmed by over a decade of annual monitoring required by the DEQ. The topic of groundwater is further discussed in the FAQ: “Is groundwater migration of contaminants a risk to the underlying aquifer or the Willamette River?”

5. The CAD cells were determined to be seismically vulnerable due to steep underwater slopes and their proximity to the deep pit under the lagoon. They were buttressed to reduce the risk of them being breached by slope failure as shown on the below cross-section figure.

6. Steep slopes, which may be seismically vulnerable, still exist in the Ross Island lagoon, as shown on the below bathymetry figure. This figure is essentially an underwater topography map. Areas where the contour lines are close together have steep slopes.

7. HeronPark plans to perform seismic assessment and design to improve the seismic stability of the existing CAD cells and cap and to provide seismic resiliency for the envisioned new cap over PHSS sediments. The seismic assessment and design would occur after HeronPark obtains commitments from the PHSS Potentially Responsible Parties for the volumes they intend to provide to HeronPark, such that it can be optimized for the expected volumes. It is anticipated that filling the deep pit under the Ross Island lagoon with PHSS sediments and the construction of the associated new cap will substantially improve the seismic resilience of the existing CAD cells and cap. It is anticipated that the seismic assessment and design would occur in the 2027-2028 timeframe. It would be included in the permit applications to the regulatory agencies, which will be public documents. No implementation of the plan would occur without prior approval from multiple regulatory agencies. The topic of seismic assessment and design is discussed further under the next FAQ: “Will the reclamation of Ross Island consider seismic stability?”

The deep pit under the Ross Island lagoon has steep underwater slopes – some over 30% – which may be seismically vulnerable. The below bathymetry figure is essentially an underwater topography map. Areas where the contours lines are close together have steep slopes.

HeronPark’s reclamation plan to fill the pit with sediments from the Portland Harbor Superfund Site (PHSS) and an associated cap and sediments from other permitted sources would make these slopes less steep and more stable.

Filling the pit to improve seismic stability is important for protecting the existing five confined area disposal (CAD) cells and cap shown on the below figure.

The CAD cells and cap are further discussed under the prior FAQ: “What is the situation with the 1990’s CAD cells in the Ross Island lagoon?”

HeronPark anticipates performing a seismic assessment and design in the 2027-2028 timeframe. It would be included in the permit applications to the regulatory agencies, which will be public documents and will involve a public comment process. No implementation of the plan would occur without prior approval from multiple regulatory agencies.

The seismic assessment will consider potential earthquakes from Portland’s local earthquake faults, including the Portland Hills fault, and from a megathrust earthquake along the Cascadia Subduction Zone. The Portland Hills fault is discussed further in a 2001 report by the Oregon Department of Geology and Mineral Industries (DOGAMI). According to DOGAMI, several lines of indirect evidence have led to the conclusion that the Portland Hills fault zone appears to be capable of generating an earthquake of magnitude 6.8 to 7.2 on average once every 1,000 years. The Portland Hills fault runs along the northeastern side of Ross Island, as shown in the below figure.

According to the Oregon Office of Emergency Management, the Cascadia Subduction Zone runs from northern California up to British Columbia and is about 70-100 miles off the Pacific coast shoreline, as shown on the below map from the U.S. Geological Survey.

There have been 43 earthquakes in the last 10,000 years within this fault. The last one occurred in 1700, with an estimated 9.0 magnitude.

Filling of the pit and the associated seismic stabilization of the existing CAD cells and cap are a top priority, because slope failure could expose substantial portions of the existing underlying contaminated sediments. Because the anticipated PHSS fill material would be placed into an existing deep pit or bowl, the material would be confined horizontally. The PHSS fill material and its new cap might experience settlement from an earthquake and potentially shear damage from a localized earthquake on the Portland Hills fault. HeronPark will propose a Financial Assurance Plan as part of its permit applications. That plan will include a post-closure-care trust (a.k.a. “endowment”), which will fund monitoring and maintenance of the reclamation plan and repair of the caps in perpetuity, including potential major repairs resulting from earthquakes.

HeronPark’s concept to fill the pit with PHSS sediments and fund a robust post-closure-care trust represents the most viable solution for improving seismic resiliency, because without it, the existing capped contaminated sediments and CAD cells would remain seismically vulnerable with no funding source to repair the damage in the event of an earthquake.

Groundwater migration will be a topic addressed in HeronPark's formal permit application to the Oregon Department of State Lands and Department of Environmental Quality in the 2027-2028 timeframe. This topic will be informed by a prior site investigation of the lagoon which found that groundwater at Ross Island generally moves upward toward the lagoon. This means contaminants are not expected to move downward into the underlying groundwater layers beneath the site. In other words, the lagoon is the water body that groundwater naturally discharges to, not the underlying aquifer. The report also concluded that this groundwater pathway up into the lagoon does not create an unacceptable risk based on the investigation results. This conclusion was supported by a flux chamber seepage study, which used chambers placed on the lagoon bottom to measure groundwater movement, and by groundwater level measurements during tidal monitoring, which showed that groundwater was moving upward toward the lagoon. These findings indicate that the deeper aquifer beneath the site is not expected to receive contaminants from the impacted sediments. Another key consideration is that the Portland Harbor Superfund Site sediments that would qualify for acceptance would contain relatively non-mobile contaminants that tend to adhere to the fine grained sediments (see the FAQ about the definition of non-hazardous).

The cap of clean sediments that will be constructed over the sediments from the Portland Harbor Superfund Site will be engineered to prevent contaminants from migrating upward into the Ross Island lagoon.

The topic of groundwater migration is also discussed under the FAQ: “What is the situation with the 1990’s CAD cells in the Ross Island Lagoon?

HeronPark envisions limited docent-led public visits to Ross Island when it is safe and when operations allow. The reclamation will coincide with the placement of sediments in the Ross Island lagoon during the dredging window for the Portland Harbor cleanup, which is primarily between July 1st and October 31st of each year to comply with state-required in-water work windows. This limited dredging window avoids impacting migratory fish. During the placement of sediments, it will be unsafe for the public to visit. Outside the dredging window, HeronPark plans to conduct other reclamation activities, such as removal of the former sand and gravel equipment and debris, removal of invasive species and planting of native plants. HeronPark anticipates that there will be intervals during winter/spring when it will be safe for docent-led groups to visit the island and observe the wildlife, habitat and reclamation progress.

Public access to the completed nature preserve will be managed by the public agency that becomes the owner of the preserve.

Yes. HeronPark anticipates a year-round staff. During the July to October dredging window, the staff will be primarily engaged with managing the secure placement of sediments in the Ross Island lagoon. In other months, the staff will focus on removing the old sand and gravel mining and processing infrastructure and the industrial debris on Hardtack Island. The staff will also be involved in managing and implementing habitat restoration activities. HeronPark will seek to hire locally, provide training, and engage with local community colleges and universities to facilitate internship and degree programs that lead to careers in environmental restoration and environmental engineering.

The reclamation plan will be designed to handle bigger floods and hotter summers that may come with climate change. 

The cap of clean material that will be constructed over the Portland Harbor Superfund Site sediments will be designed to protect it and the underlying sediments from scour during future floods. The resilience of the cap will be aided by the top of the cap being at an elevation below the river bottom. This, and the configuration of the island surrounding the cap, will help protect it from flood scour. Additionally, due to its lower elevation, the cap will gain natural deposits of clean river sediments over time, adding more protection. The cap design and its protection from future floods will be a topic addressed in HeronPark's formal permit application to the Oregon Department of State Lands and Department of Environmental Quality in the 2027-2028 timeframe.