Appeal 24878

24.50.060(F)(8)

Per Portland City Code (PCC) Section 24.50.060(F)(8) (Balanced Cut and Fill Required in All Flood Management Areas of the City Not Addressed by Section 24.50.060 G), balanced cut and fill shall be required. All fill placed at or below the base flood elevation shall be balanced with at least an equal amount of soil material removal. Soil material removal shall be within the same flood hazard area identified in Section 24.50.050(A)–(I).
a. Excavation shall not be counted as compensating for fill if such areas will be filled with water in non-storm winter conditions.
b. Temporary fills permitted during construction shall be removed.

NW Natural requests a variance under PCC Section 24.50.070 to allow the on-site excavation of 84 cy of material between the ordinary high water elevation and the base flood elevation (32.7 feet NAVD88/30.6 feet COP) to occur during implementation of the future sediment remediation.

The proposed project involves replacement of 20 damaged 12-inch treated wood fender piles with (16) 16-inch steel piles at an active dock structure consisting of six dolphin structures and two steel trestles. The dock structure is located along the Willamette River at approximately river mile (RM) 6.3 and is used to moor fuel and oil tankers, fuel barges, and tugboats. As the pile removal approach is to completely pull the damaged piles out of the substrate, the EPA Region 10 Cleanup Program is requiring the placement of a thin layer of clean sand (6 inches deep) in an approximate 15-foot radius around the piles after their removal. The area of sand cover placement is shown in Figure S3.1 in the figure set provided (see Attachment 1). Approximately 84 cubic yards (cy) of clean sand will be placed. This is a temporary measure that is being required by EPA pending completion of sediment cleanup consistent with the Portland Harbor Superfund Site Record of Decision.
The placement of clean sand triggers the need to comply with PCC Section 24.50.060(F)(8) (Balanced Cut and Fill Required in All Flood Management Areas of the City Not Addressed by Section 24.50.060 G). As such, NW Natural is required by the regulation to excavate 84 cy of soil on site between the ordinary high water elevation and the base flood elevation (32.7 feet North American Vertical Datum of 1988 [NAVD88]/30.6 feet City of Portland datum [COP]). However, a significant amount of remedial activity is planned for the Gasco Sediments Site Project Area and Gasco Upland Site in coordination with EPA and the Oregon Department of Environmental Quality (DEQ), respectively, over the next several years (see Attachment 2). The entire riverbank and adjacent upland area require remediation, as shown in Figures 2 and 3 of Attachment 2.
Due to the existing on-site contamination in the zone between the ordinary high water elevation and the base flood elevation, it is not feasible for NW Natural to excavate/remove 84 cy of material to achieve a balanced cut and fill for this proposed project until upland and in-water remedial design is complete and remediation is implemented, which is expected to occur over the next several years. It is expected that a sufficient volume of both submerged material and riverbank soil within the floodway will be removed from the site to completely offset the temporary sand cover for which NW Natural is requesting this variance.
NW Natural requests a variance under PCC Section 24.50.070 to allow the on-site excavation of 84 cy of material between the ordinary high water elevation and the base flood elevation (32.7 feet NAVD88/30.6 feet COP) to occur during implementation of the future sediment remediation. Delaying the balanced cut and fill requirements will not have an impact on the base flood elevation or water surface elevations in the floodway during a 100-year event. That conclusion is based on a hydrologic and hydraulic floodplain study that was conducted for the proposed project and which concluded that the placement of the 6-inch sand cover required by EPA on the existing grade will not result in any significant change to the base flood elevation, and there will be no measurable increase in water surface elevations within the regulatory floodway during the 100-year event (floodway encroachment) (see Attachment 3).

EPA is requiring the placement of clean sand material as part of the project. It is appropriate to delay the on-site excavation of 84 cy of material between the ordinary high water elevation and the base flood elevation (32.7 feet NAVD88/30.6 feet COP) until implementation of sediment remediation, which is also required by EPA, to achieve balanced cut and fill for the proposed project for the following reasons:
• NW Natural is completing remedial design for a sediment and riverbank cleanup under the Administrative Settlement Agreement and Order on Consent with EPA. NW Natural is also working with DEQ to develop cleanup alternatives for the uplands (see Attachment 2).
• The nominal fill volume of 84 cy will be easily accommodated as part of the sediment and riverbank cleanup project currently under design for EPA.
• Removal of upland and/or riverbank soil ahead of this site-wide remedial design and sediment remediation will uncover soil with higher chemical concentrations than are at the existing surface, which would expose ecological and human receptors to higher levels of chemical contaminants.
• EPA and DEQ (if the on-site excavation was landward of the top of riverbank) would need to be part of the on-site excavation process, which we believe would take many months and require multiple steps that would prevent NW Natural from completing the proposed project work during the 2021 in-water work window. Delaying the project would increase the potential for structural failure of the dock, limit vessel access and pose possible risk to worker safety.

As described previously, delaying the balanced cut and fill requirements will not have an impact on the base flood elevation or water surface elevations in the floodway during a 100-year event. A hydrologic and hydraulic floodplain study was conducted for the proposed project and concluded that the placement of the 6-inch sand cover as required by EPA on the existing grade will not result in any significant change to the base flood elevation, and there will be no measurable increase in water surface elevations within the regulatory floodway during the 100-year event (floodway encroachment) (see Attachment 3).

Delaying the excavation of 84 cy of soil to achieve balanced cut and fill for the proposed project will provide equivalent health, accessibility, structural capacity, energy conservation, life safety, or fire protection to what the code requires, as described in more detail below.

Health and Life Safety: Delaying when NW Natural achieves the balanced cut and fill requirements will not negatively impact health or life safety. Although the cut and fill portions of the project will not be immediately balanced, the proposed project avoids impacts to the base flood elevation, consistent with PCC Section 24.50.060.D, Provisions for Flood Hazard Reduction. A hydrologic and hydraulic analysis demonstrated that the project would result in no rise to base flood elevation (see Attachment 3), thereby providing equivalent health and life safety for the protection of Portland residents from the risk of flood. To minimize the imbalance, the EPA required sand cover is limited to the minimum area needed to protect the environment—EPA has indicated that a 15-foot radius of clean sand around each of the removed piles achieves an appropriate level of protection. Additionally, the removal of dilapidated timber fender piles improves the safety of a structure in the floodway, but also importantly removes creosote-treated wood from the river. The sand cover further supports the intent of Section 24.50.060(F)(10) that prohibits uncontained hazardous materials in flood management areas. The sand cover is a necessary project component to reduce or eliminate potential exposure to chemical contaminants that may be uncovered during pile removal activities.

Accessibility: Delaying when NW Natural achieves the balanced cut and fill requirements will have no impact on accessibility. The replacement of the damaged fender piles as part of the proposed project will improve accessibility to the dock structure.

Structural Capacity: Twenty fender piles at the existing dock were determined to be in unsafe condition, so the dock repair project was engineered by KPFF to meet structural capacity needs for continued operation of the dock. A project-specific alternatives analysis was submitted in the Joint Permit Application (PHS 2020) and found that the proposed project is the least environmentally damaging practicable alternative. The dock is otherwise in conformance with PCC Section 24.50.060(F)(4) (nonresidential structures) subsections (b) and (c) because the dock repair project will implement new “structural components capable of resisting hydrostatic and hydrodynamic loads and effects of buoyancy” and has been designed by a registered professional engineer such that “the design and methods of construction are in accordance with accepted standards of practice for meeting provisions of this subsection.” Delaying when NW Natural achieves the balanced cut and fill requirements will have no impact on the dock’s structural capacity; however, delaying the dock repairs until balanced cut and fill can be simultaneously attained may adversely affect the structural capacity of the dock itself.

Energy Conservation: Delaying when NW Natural achieves the balanced cut and fill requirements will have no impact on energy conservation.

Fire Protection: Delaying when NW Natural achieves the balanced cut and fill requirements will have no impact on fire protection.

Overall, this project involves placement of clean sand on the bottom of the Willamette River as required by EPA after pile removal. However, due to existing conditions (i.e., chemical contamination) within the uplands, riverbank and offshore sediments, excavation above ordinary high water, but below the adjusted base flood elevation to offset the placement of clean sand, is not feasible on this parcel until remediation is implemented in several years following completion of remedial design. The overall project meets the objectives of this code provision in that it is designed to balance structural capacity, life safety, and equivalent protection of health.

PCC Section 24.50.070(B) additionally instructs applicants to consider a specified list of “relevant factors and standards” in requests for a variance. The text of the code’s variance criteria is subsequently listed in bold and italicized font; each criterion is followed by Anchor QEA’s response as pertaining to this project.

1. The danger that materials may be swept into other lands to the injury of others.

The project is located fully in-water and subject to the flows of the Willamette River. Replacement fender piles will be installed to a depth of 45 feet below mudline to ensure structural stability in the floodway. The proposed sand cover material will be placed in a depositional area characterized by high fine sediment content. It is expected that over time, the sediment bed will be enhanced by the deposition of upstream sediment rather than erode. Therefore, Anchor QEA does not anticipate that the placed sand cover would be transported downstream in quantities that would cause injury to others.

1. The danger to life and property due to flooding or erosion damage.

This project is not expected to have any impact on flood water surface elevations within the regulatory floodway because the sand cover placement will not increase flood levels, as determined in the flood rise analysis required for the project (see Attachment 3). Therefore, no known or anticipated danger to life or property exists due to flooding as a result of delaying the achievement of balanced cut and fill for this project.
The placement of sand cover will be fully submerged in flood and non-flood conditions. No erosion would occur as a result of the proposed project. Accordingly, no known or anticipated danger to life or property exists due to erosion as a result of delaying the achievement of balanced cut and fill for this proposed project.

1. The susceptibility of the proposed facility and its contents to flood damage and the effect of such damage on the individual owner.

The sand cover will be fully submerged and located at a riverbed elevation of -21.6 feet NAVD88. Flooding is unlikely to have a damaging effect on the proposed project. Based on a calibrated hydrodynamic model of the Willamette River developed to support the Draft Feasibility Study for the Portland Harbor Superfund Site (Anchor QEA 2012), the maximum scour depth during the 1996 flood (representing a 100-year flood event) was estimated at a maximum of 0 to 10 centimeters (approximately 0 to 4 inches) in the reach of the river containing the project area. However, the sand will be placed around the piles to be replaced, which is in a depositional area characterized by a high content of fine material. Therefore, the maximum potential scour in an extreme flooding event would not significantly impact the 6-inch sand cover at a water depth of 21.6 feet NAVD88. In addition, any minor scour that might occur would be quickly infilled since it is a depositional area. Accordingly, Anchor QEA does not anticipate damage to the placed sand cover in the event of a flood.

1. The importance of the services provided by the proposed facility to the community.

This overall project provides necessary maintenance to the existing dilapidated fender piles to allow for safe access to vessels accessing the dock. The Gasco Dock is considered critical infrastructure as an integral component of long-term site operations and existing lease agreements. The dock is used for the import and export of products and moorage for articulated tug barges; therefore, a safe, operable dock that minimizes environmental impacts as a result of construction will have a public benefit in the Portland metropolitan area.

1. The necessity to the facility of a waterfront location, where applicable.

The proposed project is needed to repair damaged fender piles at an existing dock within the Willamette River; therefore, no alternative location is possible.

1. The availability of alternative locations, not subject to flooding or erosion damage.

The proposed project is needed to repair damaged fender piles at an existing dock within the Willamette River; therefore, no alternative location is possible.

1. The compatibility of the proposed use with existing anticipated development.

The area of the river is zoned River Industrial and Prime Industrial, and Anchor QEA is not aware of any anticipated development for this area with which this proposed project would interfere or be incompatible. The proposed project is replacement of damaged fender piles that are already part of an existing structure.

1. The relationship of the proposed use to the Comprehensive Plan and Floodplain Management Program for that area.

The proposed project is located in the Willamette River riverbed at RM 6.3 zoned as River Industrial. The project will sustain existing industrial uses of the site and is consistent with the Comprehensive Plan. The delay in achieving the balanced cut and fill requirements for this proposed project will not impact site use or consistency with the Comprehensive Plan and Floodplain Management Program.

The proposed project is a required activity to protect the existing structures in the floodway and the sand cover is required by EPA. Placement of the sand cover protects biological receptors, including Endangered Species Act-listed salmonids, from potential exposure to uncovered contaminants. Therefore, placement of the thin sand cover is consistent with the Floodplain Management Project intent to protect existing floodplain habitat for endangered and threatened fish species. Technical analysis further concluded that placement of the sand cover will not result in a rise to base flood elevations (see Attachment 3), which supports the Floodplain Management Project purpose to reduce the impacts of future flooding.

1. The safety of access to the property in times of flood for ordinary and emergency vehicles.

This proposed project is located on fully submerged land, with no possibility of access by land-based vehicular traffic. Access by marine vessels will be improved by the proposed project by addressing the safety of the existing dock. The placement of the thin sand layer will not impede access to the property by vessels. This will not be impacted by delaying the achievement of balanced cut and fill for this proposed project.

1. The expected heights, velocity, duration, rate of rise, and sediment transport of the flood waters and the effects of wave action, if applicable, expected at the site.

As described in the Draft Feasibility Study for the Portland Harbor Superfund Site (Anchor QEA 2012), the maximum scour depth expected in the area of the project (RM 6.3) during a 100-year flood (as represented by the 1996 flood) is estimated to be only 0 to 10 centimeters (approximately 0 to 4 inches); in addition, a majority of the proposed project area is net depositional and will be quickly infilled following a flood event. Therefore, no significant erosion or sediment transport is expected to occur even during extreme flood events and other critical conditions.

1. The costs of providing governmental services during and after flood conditions including maintenance and repair of public utilities and facilities such as sewer, gas, electrical, and water systems, and streets and bridges; Upon consideration of the factors listed above and the purposes of this Chapter, such conditions may be attached to the granting of variances as deemed necessary.

This variance criterion is not applicable to this proposed project.