Appeal 19079

24.50.060.F.8

Shell is obligated under federal permit conditions for in-water dock demolition work to install a sand layer over contaminated river substrate if post-demolition sediment sampling analysis reveals that the dock demolition project authorized under City of Portland Permit No. 17-216080 results in elevated surface contamination. Per a sample and analysis plan approved by the US Army Corps of Engineers, AECOM, on behalf of Shell, divided the dock demolition area up into six sediment sample areas. Within each sample area, several surface soil samples were collected and combined for analysis of several contaminants of concern. Dock demolition is nearly complete. When finished, post-demolition sediment samples will be collected. In the event that sampling identifies an increase in contaminants, Shell will be required to install a 6-inch sand layer immediately to protect water quality and reduce the potential for downstream migration of contaminated sediments.

Based on this, Shell is submitting an amendment to their existing demolition permit application to note the potential fill of a sand layer so that approvals are in place in case the sand layer is necessary. This appeal is being requested because the identified source of floodplain excavation proposed to balance the sand layer will occur later in 2019, likely after a potential sand cap would need to be installed.

Per an agreement with Portland General Electric (PGE), Shell intends to purchase floodplain excavation credits for planned excavation at PGE's Harborton property. PGE is constructing a habitat restoration project at their Harborton property at RM 3.3 (12500 NW Marina Way). The Harborton project will result in a net of about 113,000 cy of material being removed from the floodplain. The floodplain cut-fill credit agreement between PGE and Shell is attached with this appeal request

Shell may be required to construct a protective sand layer over existing contaminated river sediments at River Mile 8.7 in the Willamette River in Portland, Oregon, during the spring of 2019. The project is documented in Case File 17-216080 CO.

This is not a remedial action. The Environmental Protection Agency (EPA), while reviewing Shell's application for a Clean Water Act Section 404 permit, noted that the site should be covered with a sand layer following pile removal to reduce the potential for resuspension of contaminated sediments within the river's water column. As an alternative to placing the sand cover, AECOM, EPA, and
the US Army Corps of Engineers (USAGE) agreed to conduct pre-and post-dock demolition surface sediment sampling. Per the final USAGE permit:

"Approximately 1,100 cubic yards of sand may be placed over a maximum area of 58,160 square feet for a sand cap. A 6-inch clean sand cap may be placed over any sediment disturbed by pile removal if post-project sediment sampling reveals a significant increase in contaminated concentrations after the project is completed as compared to pre-project conditions."

If a sand cover is determined to be necessary in any of the sample sub-areas, it will be imported from an off-site borrow source. The sand to be used for the cover will be free from roots and other loose organic matter, trash, debris, snow, ice, or frozen materials. The sand source will be analyzed to ensure that it is sized medium to fine sand with trace (4%) to less than 10% fines, a minimum of 0.12 percent total organic carbon and an average density of approximately 120 pounds per cubic foot.

'to verify the clean condition and physical characteristics of the sand material source, a minimum of one, 5-point composite sample will be collected for every 400 cubic yards of sand to be collected. Samples will be tested for the following:

. PCBs as Aroclors in Solids (United States Environmental Protection Agency [EPA] Method 8082A [low level])
. PAHs (EPA Method GC/MS 8270-SIM [low level])
. Dioxin/Furans (EPA Method 1613B [low level])
. Total metals, including aluminum, antimony, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, silver, and zinc (EPA Methods ICP/MS 6020A and 7471B)
. Total petroleum hydrocarbons (TPH) as diesel and heavy oil-range hydrocarbons (Method NWTPH-Dx [silica gel cleanup])
. Bis(2-ethylhexyl)phthalate (EPA Method 8270D)
. Organochlorine pesticides (EPA Method SW8081B)
. Tributyltins (EPA Method GC/MS 8270D-SIM)
. Corrosivity by pH (EPA Method SW9045D)
. Total Solids (Puget Sound Estuary Program [PSEP] 1986 or Plumb et al. 1981)
. Total organic carbon (PSEP 1986, Plumb et al. 1981, or EPA SW9060)
. Moisture content and dry density (Standard method)
. Particle size distribution, with hydrometer (American Society for Testing and Materials [ASTM] D422)
. Direct Shear Strength (ASTM D3080 at 0.5, 1.5, and 2.5 kips per square foot)

The sand source sample data will be compared to the lower of the Portland Harbor screening level values included in Table 4 to ensure the material meets the clean fill requirements for the Portland Harbor, before it is mobilized for placement in any of the six sampling sub­ areas. Low-level analysis and laboratory-specific reporting limits will be requested to facilitate the comparison of the data to the screening level values indicated.

The sand layer would occur primarily on lands owned and managed by the Oregon Department of State Lands (DSL). The sand layer would occur entirely within the floodway of the Willamette River (Flood Hazard Zone AE).

The sand layer would be placed across the river bottom, to the limits of one or more sediment sample areas (see attached project plan set, Sheet 14). The sand layer will key into a small berm at the toe of slope to prevent lateral movement of the cap towards lower river elevations. The toe berm will be approximately 5 feet wide at its widest point and will consist of angular gravel up to 3-inch-diameter size (Sheet 15). The toe berm will be placed prior to sand placement.

The volume of fill associated with the sand layer may be up to 1,251 cubic yards (cy) and would include course sand with angular gravel along the toe berm. Where required, the temporary cover materials shall be placed from a barge using tremie or clamshell methods.
Placement methods shall ensure minimal disturbance of the underlying sediments that may be contaminated.

Volumes will be verified by pre-installation and post-installation multi-beam bathymetric survey on a 1-foot grid spacing in accordance with US Army Corps of Engineers engineering standard EM-1110-2-1003.

In general, fill slopes for the isolation sand layer and overlying gravel would be no steeper than 3 feet horizontal to 1 foot vertical (3:1) to maintain cap stability. The ballast rock would be no more than 2 feet horizontal to 1 foot vertical (2:1) along the toe of the cap.

The proposed project is scheduled for implementation in January 2019. An in-water work extension has already been granted for the project to allow for this work outside of the Oregon Department of Fish and Wildlife (OOFW) in-water work window (July 1 through October 31).

Although the project removed hundreds of piles, concrete mooring dolphins, and cross beams from the river's floodplain, the City has indicated that they do not consider any of this material removal in their floodplain cut-fill balance review. As such, Shell was advised to seek agreement with other entities planning to remove fill material from the floodplain, and to work with those entities on an agreement to use their excavation volume to offset the volume of the potential sand cover. AECOM worked with the City to identify potential sources for floodplain excavation and identified PGE as an entity with plans to remove substantial amounts of fill materials from the Willamette River floodplain just downriver from the Shell dock demolition site between river miles 2.7 and 3.7 (within the City).

PGE's Harborton property (documented in City of Portland Appeal ID 18490), is a restoration project designed to create off­ channel habitat within the Willamette River floodplain. The property is located at 12500 NW Marina Way, Portland, Oregon. The Harborton property is located where Multnomah Channel diverges from the mainstem Willamette River. This section of the river is within the Willamette River FIRM Flood Zone AE. The Harborton property is located within the Willamette River's historical floodplain. The site includes 73.8 acres of the west bank of the Willamette River and the southwestern bank of Multnomah Channel. The Harborton property includes 21.2 developed acres. The remainder of the site is a mix of shoreline and remnant native riparian and backwater floodplain habits (35.3 acres) and a diked area that has been filled with dredge spoils (17.4 acres). The diking and dredge spoils placement has disconnected the river from its historical floodplain within the property.

PGE proposes to restore and enhance undeveloped portions of the Harborton Property to serve as a restoration site. Key elements of the proposed restoration activities include excavation and re-grading of portions of the site to provide 28.1 acres of seasonally available off-channel habitat within the floodplain. Earth-moving activities will provide access to off-channel habitat that will become available when river stage is greater than 9 feet elevation (City of Portland Datum). More than 150,000 cy of soil will be removed from the Willamette River floodplain and stored in upland portions of the property where it will form a berm that protects remaining developed portions of the site from the adjacent floodplain restoration area.

Shell proposes to comply with the dock removal's balanced cut-fill requirement at the Harborton Restoration Project. All other aspects pertaining to activities at the Shell dock removal project site are unchanged relative to the initial application for demolition permit. Balancing the Shell dock removal project's fill at the Harborton site not only meets the intent of the code but has the advantage of creating ecological benefits for species inhabiting and passing through the Portland Harbor. The Harborton property is identified as a high value restoration opportunity in the City's 2009 River Plan North Reach Recommended Draft, and by the Portland Harbor Natural Resource Trustee Council's {Trustee Council) Expert Panel, as part of the Trustee's Ecological Restoration Portfolio.

At issue is the proposed timing for when the cut balance will be completed. Commencement of the Harborton Property excavation work is permitting to begin in 2019 during the next in-water work window (July 1 to October 31). This schedule precludes simultaneous excavation at the Harborton site when the potential sand cover would be installed.

To address the timing discrepancy between fill activities at the Shell dock demolition site and planned floodplain excavation at the Harborton site, PGE is requesting a variance to the balanced cut and fill requirement. allowing the cut balance for any potential sand cover fill at the Shell dock demolition site to be delayed until later in 2019. construction season, up to nine months after the potential sand cover would be installed (early 2019).

Compliance with the City's cut-fill balance requirements can be assured as both the Shell dock demolition project and the Harborton Property restoration project have been authorized by federal permit. As mentioned above, Shell's in-water work permit authorizes the placement of the sand cover if necessary