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Ross Island

Site summary

The site is located on the Willamette River (at river mile 15), about one mile south of downtown Portland. It includes several islands surrounding a lagoon. Ross Island Sand and Gravel Co. mined gravel from the lagoon between 1926 and 2001. Since 1979, the company has been required to place fill (sediment, soil, concrete and other materials) at the site to reclaim upland, wetlands and in-water areas that were previously mined and return them to a more natural state. Reclamation goals were most recently established in the 2002 Reclamation Plan. Former operations and some of the early imported fill resulted in contamination at the site that the DEQ cleanup program is managing. In 2003, DEQ established numerical screening values, measurements of contamination that are used to evaluate whether fill is suitable for placement in uplands or the lagoon. Prior to placement, all fill must be tested to confirm that is does not contain chemicals at levels that could result in harm to the humans or wildlife that use the site. DEQ's work is coordinated with several other agencies involved at Ross Island Lagoon.
ross island aerial view

What's happening now

RISG continues to place fill at Ross Island Lagoon to meet reclamation objectives. Oregon Department of State Lands, RISG, and agency partners are currently discussing an Adaptive Management Plan, which proposes some changes to the habitat locations when compared to the 2002 Reclamation Plan figures. The primary goal of the AMP is to maximize habitat benefits while reducing the volume of import fill required. Fill volumes and sources are documented in annual reports submitted to Oregon Department of State Lands.

Starting in January 2021, DEQ will begin the process of updating the chemical screening values used to evaluate what imported fill can be placed at the site (see more information in the FAQs below). The existing screening values have not been updated since 2003 and many of the values are outdated. These updates are needed so that decisions about fill placement are based on the best available science and consistent with regional dredged material evaluations for protection of human health and the environment. 

Modification to removal-fill permit for reclamation

The Oregon Department of State Lands sought comment on Ross Island Sand & Gravel Co.'s application to modify the existing removal-fill permit for reclamation of Ross Island Lagoon, which included DEQ's updated screening criteria for fill used in filling in the lagoon. Read the full public notice.

Additionally, DSL held a virtual public information session on Sept. 8, 2022.

DEQ water quality certification public notice 

DEQ approved the water quality certification for Ross Island Sand and Gravel on Oct. 13, 2022. This is related to but separate from the Oregon Department of State Land's removal-fill permit for reclamation, which includes DEQ's updated screening criteria for fill used in filling in the lagoon. This certification references the removal-fill permit to determine what is allowable clean fill in order to protect water quality. View the permit on Your DEQ Online by signing in or clicking 'Public Records and Services' and then going to permits and searching for “Dredging - Ross Island Lagoon."

Documents associated with the previous fill evaluation process are available below:



Frequently Asked Questions


Environmental investigations focused on two basic concerns. The first was whether contaminants escaped from locations where the Port of Portland disposed of dredged materials within the Ross Island Lagoon. Between 1992 and 1998, the Port of Portland received state and federal authorization to bury contaminated dredged materials from the Portland shipyard and Port terminals in underwater disposal areas, called confined aquatic disposal cells. The Port investigated whether the original disposals were properly handled and whether any contaminants escaped into the environment.

​The second concern was potential environmental impacts of upland and in-water disposals at the island complex from sources other than the Port of Portland. Ross Island Sand & Gravel, owner of the islands and lagoon, conducted an assessment to determine what, if any, effects such disposals had. The company also investigated the nature and extent of contaminant releases caused by the breaching of a Port disposal cell during gravel mining operations. The Oregon Department of Environmental Quality provided oversight and coordinated both efforts to assure that the work met objectives.

    The Port of Portland paid for investigation of the confined aquatic disposal sites. Ross Island Sand & Gravel paid for the broader investigation and continues to pay for cleanup actions under legal documents requiring them to perform necessary work and be responsible for all costs, including time spent by DEQ guiding the assessment process. ​

    Fill evaluation is the process by which DEQ and other state and federal agencies involved in Ross Island Lagoon's reclamation determine what types of material can be placed there. The 2003 Fill Evaluation scope of work outlines the various types of dredged materials that can be placed in the water at Ross Island, including some contaminated material, as long as all necessary guidelines are followed to properly contain the contamination. DEQ establishes the standards for different types of materials that can be placed in Ross Island Lagoon to ensure the fill used in the reclamation process would not pose a risk to human health or the environment. Ross Island Sand & Gravel submits annual reports documenting fill source and quality to DSL as part of the reclamation permit requirements.

    ​Starting in January 2021, DEQ will begin the process of updating the fill evaluation process. This includes re-examining the Ross Island screening criteria to better align with existing screening criteria used to evaluate sediment quality within the Lower Willamette River. These updates are needed to improve clarity in the sediment evaluation process, promote consistency and ensure that disposal decisions are based on the best available science. Updates to the fill evaluation process will support ongoing efforts to meet the 2002 Ross Island Lagoon reclamation goals.

    Three maintenance dredge projects completed during the 2020 in-water work window placed dredged sediments in Ross Island lagoon. These projects are listed below.

    • Oregon Yacht Club (USACE permit NWP-2006-401) – ~41,000 CY
    • City of Gladstone, Meldrum Bar (USACE permit NWP-1995-833) – ~8,000 CY
    • Willamette Sailing Club (NWP-1998-179) – ~20,000 CY​

    Depending on work being performed, Ross Island Sand & Gravel operates under three separate, but closely related, regulatory systems. The Oregon Department of State Lands regulates placement of reclamation fill within the island complex (Oregon DSL permit 9819-RF [RF-26]). Fill operations are also covered by the federal Clean Water Act section 404 permit process administered by the U.S. Corps of Engineers (USACE permit NWP-1999-1500). The Department of Environmental Quality plays a decisive role in the Corps section 404 process through state authority to issue or deny a section 401 certification. A 401 Certification from DEQ puts the state on record that certain in-water activities will not violate water quality standards.

    Ross Island Sand & Gravel Company owns the majority of Ross and Hardtack islands, and the lagoon created between them. The islands have been under private ownership since the early 1900s. A portion of Ross Island on the northeast side (45 acres) was deeded to the City of Portland in 2007. The Port of Portland owns 6.5 acres at the northern tip of Ross Island.

    Ross Island Sand & Gravel no longer mines sand and gravel from Ross Island Lagoon. Onsite gravel mining ceased in 2001. RISG continued to process import materials at their processing facility on Hard Tack Island until late 2019. Permitted activities that continue are limited to placement of fill for reclamation.

    Under the 2002 Reclamation Plan, over 4.7 million cubic yards of material have been placed at Ross Island Lagoon.

    Environmental Cleanup Site Information Number: 2409 
    County:  Multnomah 
    City:  Portland
    Region: Northwest  


    Project Manager: Sarah Greenfield, 503-229-5245


    Cleanup: Sarah Greenfield, DEQ Cleanup Program

    Portland Sediment Evaluation Team: James Holm, U.S. Army Corps of Engineers

    Harmful Algal Blooms: Oregon Health Authority

    Water Quality: Jeff Brittain, DEQ 401 Water Quality Program