Abandoned Tanner Creek Sewer and 9Th and Lovejoy Street Investigation Summary Report

Abandoned Tanner Creek Sewer and 9th and Lovejoy Street Investigation Summary Report

Portland, Oregon ECSI File # 5328

Prepared for Portland Terminal Railroad Company 3500 NW Yeon Avenue Portland, Oregon

January 2015

Prepared by

Executive Summary

The Oregon Department of Environmental Quality (DEQ) requested that Portland Terminal Railroad Company evaluate contamination discovered in the Abandoned Tanner Creek Sewer (ATCS) and in soil and groundwater in the City of Portland (City) right-of-way near the intersection of NW 9th Avenue and NW Lovejoy Street in Portland, Oregon. This evaluation was to assess the exposure risk for potential receptors to contaminants of interest that have been identified in the soil and groundwater in this area. The specific exposure pathways DEQ identified for this evaluation included: direct soil exposure, vapor intrusion, groundwater migration via existing underground utilities and their back fill material to the Willamette River, stormwater runoff through former and existing utilities to the Willamette River, and river sediment. This evaluation yielded the following conclusions: 1. Multiple potential sources of contaminants of potential interest may have adversely affected the identified area of interest. These potential sources include but are not limited to the former manufactured gas plant, former nearby asphalt plant and steel foundry, former leaking underground storage tanks and above ground storage tanks in the vicinity, as well as historical City road-coating practices. 2. Soil and groundwater data from near NW 9th Avenue as well as within and adjacent to the ATCS were compiled and compared to risk-based concentrations. Concentrations of contaminants of interest were found in the soil and groundwater in the area that exceed risk-based concentrations for the unprotected excavation worker scenario. However, the City has policies and procedures in place to eliminate this risk pathway by requiring proper protection for excavation workers in this area. 3. Stormwater data from conveyance pipes in the area and City’s Outfall 11, as well as sediment data from near Outfall 11 were compiled and screened to determine if the stormwater pathway to the Willamette River posed a risk to potential receptors in the river. The data evaluated indicates that neither stormwater nor groundwater are a source of contaminants of interest at concentrations that would pose an unacceptable risk to potential ecological receptors in the Willamette River. Consistent with this conclusion, in the evaluation of Portland Harbor data, no area of potential concern was identified adjacent to OF-11 or near the severed and plugged historic ATCS outfall to the north. Underground utility lines in this area do not provide a significant preferential pathway for contaminants of interest to migrate to the Willamette River. 4. Air monitoring data from properties near NW 9th Avenue and NW Lovejoy were compiled and compared to risk-based concentrations. This data indicates the street and sidewalk pavement are effective in eliminating vapor intrusion as a potential exposure pathway. This evaluation demonstrates that contamination found beneath the intersection of NW 9th Avenue and NW Lovejoy Street does not pose an unacceptable risk to human and ecological receptors because current controls are effective at eliminating or reducing the only potential risk identified.

Contents

Section Page 1 Introduction...... 1 1.1 Purpose ...... 1 1.2 Objectives ...... 1 1.3 Report Organization...... 1 2 Background...... 3 2.1 Area of Interest ...... 3 2.2 Environmental Setting ...... 4 2.3 Existing Environmental Investigations ...... 4 3 Potential Sources, Pathways, and Contaminants of Interest ...... 11 3.1 Potential Sources...... 11 3.2 Contaminants of Interest Identified in the Area ...... 12 3.3 Pathways Reviewed ...... 12 4 Data Review and Interpretation ...... 13 4.1 Soil ...... 13 4.2 Groundwater...... 14 4.3 Stormwater ...... 14 4.4 Sediment ...... 15 4.5 Air ...... 15 5 Potential Risk Exposure Pathway Summary ...... 17 5.1 Air ...... 17 5.2 Soil ...... 17 5.3 Groundwater...... 17 5.4 Stormwater ...... 18 5.5 Sediment ...... 18 6 Findings and Conclusions...... 19 7 References...... 21

Tables (at end of text) 1 Analytical Summary of Soil Samples along NW 9th Avenue 2 Analytical Summary of Soil and Water Samples from within or adjacent to ATCS 3 Analytical Summary of Groundwater Samples along NW 9th Avenue 4 Analytical Summary of Stormwater Samples for the 27-inch Storm Sewer, Tanner Creek CSS, and Outfall 11 5 Analytical Summary of River Sediment Samples near Outfall 11 6 Analytical Summary of Air Monitoring Data

Figures (at end of text) 1 Area of Interest Including Sewer Lines near NW 9th Avenue and NW Lovejoy Street 2 Nearby Site Features, Soil and Water Samples Locations Collected from ATCS 3 1901 Sanborn Map of Pintsch MGP area 4 1908 Sanborn Map of Pintsch MGP area

III CONTENTS CONTINUED

5 Larger‐scale view, 1908 Sanborn Map of Pintsch MGP area 6 Soil Samples along NW 9th Avenue 7 Groundwater Samples along NW 9th Avenue 8 Stormwater Sample Locations in 27 inch Storm Sewer and Tanner Creek CSS 9 Sediment Samples around City of Portland Outfall 11 10 Approximate Areas Exceeding Excavation Worker RBCs

Attachment 1 DEQ Figure of Lower Drainage Area for Tanner Creek & Environmental Clean-up Sites

Acronyms and Abbreviations

AST above ground storage tank ATCS Abandoned Tanner Creek Sewer

BES Bureau of Environmental Services bgs below ground surface

CDF controlled-density fill City City of Portland CSS combined sewer system

DEQ Oregon Department of Environmental Quality

ECSI Environmental Cleanup Site Information ft foot or feet

JSCS Joint Source Control Strategy

LNAPL light non-aqueous phase liquid

MGP manufactured gas plant

OF outfall

P&DC Processing and Distribution Center PAH polynuclear aromatic hydrocarbon PTRR Portland Terminal Railroad Company

RBC risk-based concentration

SCE Source Control Evaluation SLV screening level value SVOC semi-volatile organic compound

TPH total petroleum hydrocarbon

USPS U.S. Postal Service UST underground storage tank

VOC volatile organic compound

1 Introduction

1.1 Purpose The Oregon Department of Environmental Quality (DEQ) requested that Portland Terminal Railroad Company (PTRR) evaluate contamination discovered in the Abandoned Tanner Creek Sewer (ATCS) and in soil and groundwater in the City of Portland (City) right-of-way near the intersection of NW 9th Avenue and NW Lovejoy Street in Portland, Oregon. This evaluation is to determine whether it poses a risk to human or ecological receptors and whether there is a potential for contaminants to reach the Willamette River. PTRR formerly owned property near the NW 9th and Lovejoy intersection, which was leased and operated as a Pintsch manufactured gas plant (MGP) from 1893 until the 1930s. PTRR conducted a review of reports from existing environmental investigations along NW 9th Avenue from just south of NW Lovejoy Street to Northwest Naito Parkway. PTRR analyzed available environmental analytical data associated with the City’s ATCS and nearby areas as part of this investigation. This report presents the results of that evaluation. The NW 9th Avenue and NW Lovejoy Street intersection has been assigned the DEQ Environmental Cleanup Site Information (ECSI) identification number 5328 (DEQ, 2012). As agreed to by DEQ in the Phase 1 work plan (CH2M HILL, 2011) and in subsequent meetings, this voluntary investigation involved compilation and evaluation of existing data. DEQ stated that if it is demonstrated that contamination does not pose a risk to human and ecological receptors, the Voluntary Letter Agreement with DEQ will be terminated, and environmental cleanup files will be updated to confirm no further investigation or other action is required by Portland Terminal Railroad Company (DEQ, 2010). 1.2 Objectives The objectives of this investigation summary are the following: • Evaluate available data to assess the nature and extent of contamination • Evaluate whether the known sources of contaminants of interest are ongoing or have the potential to reach the Willamette River at unacceptable levels • Evaluate whether current controls are effective at eliminating or reducing potential risks to human and ecological receptors and if any additional characterization is needed 1.3 Report Organization This report is divided into the following sections: • Background • Potential Sources, Migration, and Contaminants of Interest • Data Collection and Interpretation • Exposure Pathway Summary • Findings and Conclusions

2 Background

Northwest 9th Avenue is a public right-of-way located within the northern portion of the City’s central downtown core. The ATCS is located beneath NW 9th Avenue (Figure 1). On either side of NW 9th Avenue are identified DEQ ECSI sites including the Former Hoyt Street Railyard (1080), Horse Barn/ Union Station (2407), U.S. Postal Service (USPS) (2183), and Pearl Block (4960) (Figure 2). This area is transitioning from commercial/ warehouse/ industrial land uses to mixed commercial and urban residential land uses. As part of this transition, contamination has been evaluated and remediation activities implemented on these properties. The reports from environmental investigations conducted on these properties were reviewed and are summarized in this section. 2.1 Area of Interest The area of interest for this investigation, shown in Figures 1, 2 and 10, is shallow (less than 15 feet below ground surface [ft bgs]) soil and groundwater below the public right-of-way, at and near the intersection of NW 9th Avenue and NW Lovejoy Street. NW 9th Avenue is paved, with underlying utilities both active and abandoned. The two sewer lines beneath the NW 9th Avenue and NW Lovejoy Street intersection are a 27-inch municipal storm sewer line (the 27-inch Sewer) and the ATCS. The 27-inch Sewer is constructed of a vitrified-clay storm-sewer pipe. This line discharges into the Tanner Creek combined sewer system (CSS), at the intersection of NW Naito Parkway and NW 9th Avenue. The Tanner Creek CSS discharges to the Willamette River from the City’s combined Outfall 11 (OF-11), located just north of NW 9th Avenue (Figure 1). Neither the 27-inch Sewer nor the Tanner Creek CSS have ever been connected to the ATCS. The ATCS was a sewer line constructed in the late 1800s to contain Tanner Creek and provide drainage for an area of approximately 2.6 square miles, southwest of the former ATCS sewer outfall. The ATCS was abandoned in the early 1900s (City of Portland Bureau of Environmental Services [BES], 2011). RETEC (2004) provides the following summary description of the former Tanner Creek and the ATCS: Originally, Tanner Creek was a free-flowing stream that drained Portland’s West Hills and portions of Portland between the West Hills and the former (Hoyt Street) railyard. The creek flowed through the general area of the former rail yard and discharged to the Willamette River. In the late 1800s, Tanner Creek was contained in a brick sewer (constructed between 1887 and 1890). This early brick sewer was approximately 5 feet wide by 7.5 feet high and ran under N.W. 9th Avenue at a depth of approximately 12 to 16 feet. City of Portland sewer maps show several abandoned side sewers in the area that connected to this early brick Tanner Creek Sewer. This early brick sewer was reportedly sealed and filled with sand because it was structurally failing and was replaced by the current concrete Tanner Creek Sewer located under N.W. 10th Avenue. The ATCS was abandoned and its outfall located beneath Centennial Mills was plugged by 1917 when it was replaced by the current Tanner Creek CSS running beneath NW 10th Avenue (AMEC, 2007 and Hart Crowser, 2013). During construction of the Tanner Creek CSS between 1915 and 1917, the ATCS was permanently severed where it crosses NW Naito Parkway (formerly NW Front Avenue) (Hart Crowser, 2013). A portion of the ATCS was further sealed in 2006 as part of construction at the NW Marshall crossing upstream of the severance point by placing controlled-density fill (CDF, a lean mixture of cement grout and aggregate) into the breached portion of the ATCS. AMEC (2007) reported that, after CDF placement, no additional oily water was observed in the excavation, and characterized the condition of this seal as “much better than the integrity of the original pipe, which was observed to be leaking upon the initial discovery of the abandoned line.” In 2009, the ATCS was breached during environmental investigation on the Centennial Mills Site downstream of the severance point and immediately upstream of the former outfall. CDF was again used to

3 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT fill the discovered void and seal the ATCS (Hart Crowser, 2013). The locations of CDF placements are shown in Figure 10. 2.2 Environmental Setting 2.2.1 Topography The topography within the area of interest is generally flat with an elevation of approximately 30 ft. 2.2.2 Geology The area of interest lies within the Willamette River Valley bordered to the west by the coastal range and the east by the Cascade Range. The intersection of NW 9th Avenue and NW Lovejoy Street is within 0.25 mile of the west bank of the Willamette River. The near surface geology along the west bank of the Willamette River is composed of alluvium typical of a low sinuosity river with deposits ranging from approximately 50 to 100 ft thick (AGRA, 1996). The alluvium overlies the Troutdale Formation. 2.2.3 Soil Most of the native surface soil in this area has been covered by fill and the natural stratigraphy of this area may have been modified by re-grading and construction activities. Fill thicknesses can range up to 25 ft bgs. The fill material is described as a mixture of soil of various size, classes and manmade materials and debris, such as brick, wood, slag, and other material (DEQ, 2003). Dredge sands underlie this material, with Quaternary alluvial soil and lacustrine deposits at greater depths (AGRA, 1996). 2.2.4 Hydrogeology Shallow groundwater is typically found approximately 10 ft bgs, but may range up to 20 ft bgs (DEQ, 2003). Groundwater flow is influenced by the presence of utility lines such as the ATCS and the 27-inch Sewer near NW 9th Avenue and NW Lovejoy Street, but ultimately flows north-northeast toward the Willamette River.1 Deeper groundwater in the area of interest is part of the Troutdale Gravel Aquifer composed of dense gravels and sands. Groundwater in the Troutdale Gravel Aquifer flows northeast toward the Willamette River (DEQ, 2003). 2.3 Existing Environmental Investigations Investigations near and adjacent to NW 9th Avenue in the area of interest have occurred primarily on neighboring ECSI sites, where soil and groundwater samples were collected. Two opportunistic sampling events occurred within the ATCS when the ATCS was encountered during construction activities. Stormwater has been collected from the 27-inch Sewer, Tanner Creek CSS, and OF-11 in several events. In addition, sediment sampling near OF-11 was conducted in conjunction with the Portland Harbor Remedial Investigation and the City’s Centennial Mills Upland Source Control Evaluation (SCE). 2.3.1 NW 9th Avenue Investigations In recent years, the ATCS was encountered on three known occasions by construction workers beneath a portion of NW 9th Avenue. The first encounter occurred on October 30, 2002, while workers were installing a new storm sewer connector at NW 9th Avenue and NW Marshall. This connector was installed to route stormwater from the redeveloped Horse Barn site (also referred to as the Station Place site, Figure 2) to the active 27-inch Sewer. The second encounter occurred on March 11, 2010, during excavation work associated with the relocation of a manhole within NW 9th Avenue at NW Lovejoy. The third encounter occurred in 2009 during the Centennial Mills SCE. Figure 2 shows these three locations. The analytical results indicated

1 An exception to be noted is that groundwater monitoring at the former Hoyt Street Railyard near the northern portion of the ATCS has shown a marked change in shallow groundwater flow direction to the southeast due to commercial redevelopment activities (Integral, 2013).

4 SECTION 2. BACKGROUND

presence of polynuclear aromatic hydrocarbons (PAHs) above DEQ’s risk-based concentrations (RBCs) for excavation worker scenario. During the 2002 sewer-connector construction work, hydrocarbon-stained soil was observed outside the ATCS and oily water was observed seeping out of the ATCS through joints in its brick sides. When the top of the ATCS was accessed through an exploratory hole, oily water and oil-saturated sand were observed inside (AMEC, 2007). The access hole in the ATCS was sealed as part of construction by placing CDF inside the ATCS. After CDF placement, no additional oily water was observed in the excavation, and characterized the condition of this seal as “much better than the integrity of the original pipe…” (AMEC, 2007). When the ATCS was encountered during the City’s manhole installation at NW 9th Avenue at NW Lovejoy in March 2010, approximately 280 ft south of the 2002 sewer construction work, samples of water and soil were collected within and immediately adjacent to the ATCS. The severed northern end of the ATCS was encountered in 2009 during the Centennial Mills SCE just upstream of the plugged former outfall (see Figure 1). The ATCS was breached during test pit sampling around an old underground storage tank pit. Materials inside the ATCS and directly outside the ATCS were sampled. The void found in the breached ATCS was filled with CDF and the test pit was backfilled with excavated soil. It was noted in this report that by 1917, the ATCS had been severed where it crosses NW Front Avenue (Hart Crowser, 2013). Opportunistic sampling events associated with these encounters were the following: • Soil sample collected in 2002 at NW 9th Avenue and NW Marshall during storm sewer improvements (Hafley, 2006) • Soil sample collected in 2009 within and near the severed northern end of the ATCS during Centennial Mills SCE (Hart Crowser, 2013) • Water sample collected in 2010 within the ATCS during manhole relocation at NW 9th Avenue at NW Lovejoy (O’Donovan, 2010) Sample locations for these opportunistic sampling events are presented in Figure 2 and a summary of the analytical results are presented in Table 2. 2.3.2 Neighboring Properties’ Investigations Reviewed This evaluation included review of documents produced by neighboring properties to gather additional data on concentrations of contaminants that were found in the City’s right-of-way below the intersection of NW 9th Avenue and NW Lovejoy Street and to help identify potential contaminant sources and migration pathways. This evaluation identified several properties bordering NW 9th Avenue where contamination has been identified, which are now under Records of Decision, primarily for PAHs and metal-related contamination. The following investigations were reviewed: • USPS Processing and Distribution Center (P&DC) site investigation and remediation (Arcadis, 2005 and 2006) • Horse Barn site investigation and remediation (AMEC, 2001, 2002, 2007, and 2009) • Former Hoyt Street Railyard site investigation (RETEC, 1996) • Tanner Creek Sewer Investigation and Evaluation (RETEC, 2004) • Centennial Mills SCE (Hart Crowser, 2013) • City of Portland Outfall 11 Investigation (BES, 2011) These investigations are described below. The relevant properties are identified in Figure 2.

5 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT 2.3.2.1 USPS Processing and Distribution Center During the remedial investigation of the USPS P&DC site, historical activities were examined focusing on four primary operational areas. Of these four areas, only the northwest corner of the USPS site is relevant to the environmental conditions along NW 9th Avenue. This area is where the former MGP was located. The former MGP was in operation from 1893 until the 1930s to produce compressed gas from naphtha-grade oil for lighting rail coaches. The principal contaminant of concern in this area is petroleum hydrocarbons in the soil and shallow groundwater (Exponent Inc., 2012). The soil in this area was found to exceed RBCs for the following: • Excavation worker incidental ingestion of surface/subsurface soil scenario for benzo(a)pyrene • Occupational worker volatilization from soil to outdoor air scenario for naphthalene • Excavation worker through direct contact with shallow groundwater in an excavation scenario for benzo(a)pyrene and naphthalene (DEQ, 2010) Construction of what is now the ATCS (1887-1900) was generally concurrent with the construction of the former MGP, believed to be sometime between 1889 and 1901, based on historical Sanborn Maps. Based on this information, it is believed that the ATCS was present and active beneath NW 9th Avenue for the early part of the MGP’s operation, until the sewer was abandoned between 1915 and 1917 and replaced with the current Tanner Creek CSS running beneath NW 10th Avenue (AMEC, 2007). The MGP would have continued operating for 15 to 20 years after the ATCS beneath NW 9th Avenue was abandoned by the City (Arcadis, 2005 and 2006). Residues that could be from the MGP have been documented at sites adjacent to NW 9th Avenue, specifically at the USPS P&DC, the Horse Barn Site, the Lovejoy Ramp, and the Former Hoyt Street Railyard. The DEQ-accepted remedial actions for the USPS P&DC site under its current use as a mail sorting facility include the following: • Institutional and engineering controls • Maintenance of existing site cover paving and buildings • Limited worker activity around the former MGP area • An established Contaminated Media Management Plan specifying protocols for worker notification and requirements for PPE, dust suppression, soil and groundwater management • Site access restrictions 2.3.2.2 Former Horse Barn Property The Former Horse Barn Property is in a former low-lying area that was filled and developed as a PTRR rail yard in the early 1900s. As use of the rail yard diminished, a portion of the site was used as a horse barn for the City Mounted Police. The area is now referred to as Station Place and is being redeveloped containing mixed use commercial and residential structures. The Horse Barn site is made up of seven individual lots, all of which have been redeveloped except Lot 5 on the northern end of the property. Redevelopment has included construction of a roadway ramp, an office building, a hotel, a residential tower, and a multi-level parking garage. Site environmental investigations were initiated in October 1999 and continued through 2003. These investigations focused on the contamination attributed to the former MGP, which was located just south of the southwest corner of the site and expanded to identify residual contamination attributed to the former rail yard and a number of underground storage tanks. Multiple exploration phases included soil and groundwater sampling at depths ranging from surface to 100 ft bgs (AMEC, 2001). The soil at this site was found to have elevated PAHs, lead, arsenic, and total petroleum hydrocarbons (TPHs) at shallow depths throughout the site. Volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs) (other than PAHs), and cyanide were only detected in a few samples generally associated with the MGP waste in the southwest corner of the site. PAHs and TPHs were found at elevated

6 SECTION 2. BACKGROUND

concentrations throughout the site and at hot spot concentrations in the southwest corner of the site (MGP- type waste). Contaminant concentrations generally decrease with depth and are not present in native soil underlying site fill (approximately 25 ft bgs), except in the MGP area. In 2001 and 2002, the soil identified as containing hot spot concentrations were excavated and transported to the Hillsboro Landfill for disposal. The hot spot soil could not be fully removed to the south and west without undermining the Lovejoy Ramp (south) or the sidewalk adjacent to NW 9th Avenue (west). Benzo(a)pyrene concentrations in the soil were found to exceed risk-based concentrations for the construction worker and excavation worker scenario across the site and under the Lovejoy Ramp (to the south) (DEQ, 2003). Elevated concentrations of VOCs, SVOCs (principally PAHs), TPHs, and inorganic constituents were found in the site groundwater with the highest concentrations found in the southwest corner of the site. Benzo(a)pyrene, benzene, and naphthalene concentrations in the groundwater were found to exceed risk- based concentrations for the construction worker and excavation worker scenario in the southwest portion of the site and under the Lovejoy Ramp (to the south) (DEQ, 2003). The DEQ-selected remedial actions for this site, which were implemented by the Portland Development Commission (AMEC, 2001) include: • All portions of the site were capped with 2 ft of clean fill. Where site development occurred, asphalt or concrete was substituted for a portion of the clean fill cover. A demarcation layer was installed in selected areas to mark the boundary between contaminated soil and clean fill • Vapor barriers and a passive venting system were installed in the buildings to prevent potential accumulation of organic vapors in the southwest portion of the site • Groundwater monitoring was conducted to determine the potential for off-site migration • Institutional controls were put in place to identify potential site risks. This included a contaminated media management plan, inspection and maintenance plan, soil and groundwater management plan, and worker notification and protection plan, and prohibition for onsite groundwater use 2.3.2.3 Former Hoyt Street Railyard The Former Hoyt Street Railyard site was also a former low-lying area that was filled and developed as a roundhouse, railroad engine fueling station, and railyard in 1911 (Greenburg, 2008). Environmental investigations and remediation at this site date back to the late 1970s. Soil with elevated concentrations of contaminants of interest was found in seven general areas across the site; however, only two of these seven general areas were in proximity to NW 9th Avenue. These were identified as the “Second Fueling Area” and the “MGP Impacted Area.” The area identified as the Second Fueling Area was located just west of NW 9th Avenue and was used to fuel locomotives from the mid-1940s until 1997. Residual light non-aqueous phase liquid (LNAPL) was found in this area and petroleum hydrocarbons were found in elevated concentrations in the soil from 7 to 23 ft bgs and in the groundwater in this area (DEQ, 2000). Soil and associated LNAPL were removed in 2001. The area identified as the MGP Impacted Area, was the Former Hoyt Street Railyard area across the intersection of NW 9th Avenue and NW Lovejoy Street from the former MGP. Hydrocarbons found in this area were detected in the soil from 15 to 29 ft bgs and contained more VOCs and PAHs than the hydrocarbons in other areas of the site (DEQ, 2000). Benzo(a)pyrene was found to exceed risk-based screening values for construction workers and future urban residents (adult and child) in this area (DEQ, 2000). Remedial actions identified by DEQ included: • Capping the entire site with 2 to 3 feet of clean soil. Buildings, pavement, or other site improvements were considered part of the cap. Inspection and long-term maintenance of the cap • Fencing and other site security measures to prevent public access

7 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT • Establishing a Contaminated Media Management Plan • Notifying DEQ should site use change • Excavating soil in utility corridors where concentrations exceed the construction worker risk-based concentrations in the upper 5 feet of soil • Continuing operation of the existing LNAPL recovery system until the 2001 soil/LNAPL removal • Investigating and evaluating the Tanner Creek CSS and backfill • Groundwater monitoring 2.3.2.4 Tanner Creek Combined Sewer System The Tanner Creek Sewer Investigation and Evaluation (RETEC, 2004) was reviewed for information on whether the Tanner Creek CSS and the 27-inch sewer line provide a pathway for contaminants of interest located in the City’s right-of-way near NW 9th Avenue and Lovejoy Street to the Willamette River. Neither the Tanner Creek CSS nor the 27-inch sewer have been connected to the ATCS, but reports related to those sewers were reviewed for additional background information and any indications of these conduits providing a preferential pathway for contaminants of interest by potentially contaminated groundwater travelling through the back fill or infiltration into the pipelines. The Tanner Creek CSS runs along NW 10th Avenue, a block to the west of the ATCS, which runs beneath NW 9th Avenue. Near its northern end, the Tanner Creek CSS turns to the northeast and intersects the path of the ATCS at the point at which the ATCS is severed as shown in Figure 1. RETEC investigated and evaluated the Tanner Creek CSS as required by the Former Hoyt Street Railyard Record of Decision to determine if that sewer line, or the material used to backfill the excavation around the sewer line, was providing a preferential pathway for contaminants of interest to reach the Willamette River (RETEC, 2004). RETEC reviewed historical documents to identify alignment, construction methods, and historical reports of contaminants in the sewer or sewer backfill. RETEC also video logged the existing active sewer lines, collected soil samples of backfill surrounding the Tanner Creek CSS, sampled groundwater in the backfill surrounding the Tanner Creek CSS, and sampled water within the Tanner Creek CSS during high and low water flow, and discharge from OF-11 to the Willamette River (RETEC, 2004). DEQ approved the completion of the investigation. RETEC concluded and DEQ concurred that some petroleum hydrocarbons in very low concentrations were present in the soil and groundwater outside the Tanner Creek CSS from various sources but at levels that did not pose an unreasonable risk to or a significant adverse effect on ecological and human receptors (RETEC, 2004 and Greenburg, 2008). 2.3.2.5 Centennial Mills The Centennial Mills SCE report was reviewed to identify whether the ATCS may have provided a migratory route for contaminants of interest to the Willamette River. As part of the Centennial Mills SCE, Hart Crowser conducted a review and sampling of the ATCS and the current Tanner Creek CSS. The ATCS discharged water under the Centennial Mills site from approximately 1887 through 1917. The ATCS was abandoned, filled with sand, and plugged at the outfall by 1917. The ATCS was also severed by 1917 at NW Front Avenue, where the Tanner Creek CSS crossed the ATCS. In 2009 during the Centennial Mills SCE work, CDF was placed in the void found in the ATCS where it entered the Centennial Mills site. Material inside the ATCS at the Centennial Mill site was sampled and found to contain TPHs and PAHs at levels well below cleanup levels. Stormwater samples were collected from the current Tanner Creek CSS and found to contain only low concentrations of PAHs (just above reporting levels) (Hart Crowser, 2013). An assessment of river sediment quality adjacent to the Centennial Mills site was completed as part of the SCE (Hart Crowser, 2013 and DEQ, 2014). Based on the analytical results of the sediment samples collected during the investigation of the Portland Harbor Superfund Site, the U.S. Environmental Protection Agency did not identify an area of potential concern at or near the former outfall of the ATCS (LWG, 2012).

8 SECTION 2. BACKGROUND

Additional surface sediment samples collected during the Centennial Mills SCE adjacent to the former ATCS outfall and the current Tanner Creek CSS outfall (OF-11) were found to be nondetect or below screening level values, indicating they are not a source of contamination to the river. Chemical analysis on soil and groundwater collected by Hart Crowser adjacent to the Tanner Creek CSS do not indicate a significant contaminant pathway, as such it can be concluded that the sewer’s backfill is not a former or ongoing pathway for contaminants to the river (Hart Crowser, 2013). 2.3.2.6 City of Portland Outfall 11 Investigation DEQ requested an evaluation of the potential for contaminants of interest to migrate from the area of interest to the Willamette River via infiltrating leaks in the existing stormwater conveyance system. The City’s Tanner Creek Water Quality Characterization report was reviewed to evaluate this potential. BES conducted a water quality characterization study of the Tanner Creek CSS OF-11 to determine if the outfall provides water that is suitable for off-channel fish habitat. BES conducted sampling from a Tanner Creek CSS manhole within Naito Parkway during dry and wet seasons from 2008 through 2010. Based on the results of this study, the City found that there are detectable concentrations of contaminants of interest discharging from Tanner Creek CSS (at OF-11), but not at levels that would pose an unacceptable risk to environmental receptors. The source(s) of the detected contaminants of interest were not identified. BES determined that water quality at OF-11 is comparable to similar urbanized outfalls and speculated that up-pipe remediation activities will continue to improve water quality (BES, 2011). Therefore, the pathway for potential migration of contaminants from the area of interest into the 27-inch Sewer or the Tanner Creek CSS and discharge to the Willamette River via OF-11 is insignificant.

3 Potential Sources, Pathways, and Contaminants of Interest

This section summarizes the potential sources of contamination and contaminants of interest for the NW 9th Avenue and NW Lovejoy Street area as well as the ATCS. 3.1 Potential Sources There are multiple potential sources contributing to the contamination identified in soil and groundwater beneath the City’s right-of-way at and near the intersection of NW 9th Avenue and NW Lovejoy Street. These potential sources include the former MGP, former nearby asphalt plant and steel foundry (Figure 2), former leaking underground storage tanks (USTs) and above ground storage tanks (ASTs) in the vicinity, historical City road-coating practices, and a historical gas holder. A discussion of potential sources is provided below. 3.1.1 Manufactured Gas Plant The MGP was located at the southeast corner of what is now the intersection of NW 9th Avenue and NW Lovejoy Street. Arcadis (2006) reported that the MGP operated from approximately 1883 until the early 1930s. Because the MGP was not depicted on the 1889 Sanborn Fire Insurance Map, but is shown on the 1901 and 1908 Sanborn Fire Insurance Maps, it appears that the MGP was constructed between 1889 and 1901. Figures 3 through 5 show how the MGP was depicted on the 1901 and 1908 Sanborn Fire Insurance Maps (sheets 102 and 46, respectively). The 1901 Sanborn map shows the MGP as positioned on fill near the edge of an area delineated with the notation “low ground” to the north and west. The curved line passing the footprint of the MGP is noted on the map as “top of bank,” indicating that the plant was constructed on what was essentially a small peninsula of filled land just south and east of an area of low ground. The 1901 map indicates the rail yard to the east of the MGP is “planned.” By 1908, the PTRR rail yard and much of the area surrounding the MGP had been filled and developed for industrial use, including a foundry and an asphalt plant across NW 9th Avenue from the MGP (Figure 4). Electric lamps were installed in railcars in the early 1930s and compressed gas used for lighting rail cars was no longer needed. Thus, it is approximated that the MGP stopped operations in the early 1930s, although records indicate the structure remained in place at least as late as 1934. There was speculation in a previous report (Hart Crowser, 2013) that there may have been a direct connection between the MGP and the ATCS; however, there has been nothing to suggest that this speculation has any merit. During the extensive site investigations and redevelopment-related construction completed over the past 15 years in the areas around the MGP, no historical connections to the ATCS from either the Horse Barn site (location of MGP-related residues in the subsurface) or the USPS P&DC site (former location of the MGP and the location of MGP-related residues) were identified. In addition, when the ATCS was abandoned and the Tanner Creek CSS constructed, the MGP was still in operation and no lateral lines were identified. The “several abandoned side sewers” noted by RETEC (2004) based on its review of City sewer maps were located either beneath NW Quimby, NW Overton, or NW Marshall, and west of NW 9th (the MGP was east of NW 9th) and not connected to or adjacent to the former MGP (see Figure 2). 3.1.2 Historical Asphalt Plant and Steel Foundry The 1908 Sanborn Map of the area near NW 9th Avenue and NW Lovejoy Street show both an asphalt plant as well as a steel foundry (Columbia Steel Company) directly northwest and southwest of the MGP. The Sanborn Map identifies the historical asphalt plant manufacturing and storing asphalt and fuel oil, both of which were potential sources of PAHs at the time. The steel foundry had an open coke bin and underground oil storage, providing additional potential sources of PAHs and TPHs. According to the figure provided by

11 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT DEQ (See Attachment 1), there was a lateral line connecting to the ATCS that ran adjacent to the asphalt plant and the foundry. 3.1.3 USTs and ASTs in the Vicinity The 1908 Sanborn map presented in Figure 5 identifies AST fuel oil storage and underground oil storage near the ATCS that may have been sources of PAHs. DEQ has identified a number of leaking USTs near the ATCS at NW 9th Avenue and NW Lovejoy Street. Depending on the extent of the leakage and the proximity to the ATCS, these are also potential sources of TPHs and PAHs into the ATCS. 3.1.4 Historical Road Maintenance Coal tar and oil tar were used extensively for road construction from the time that engineers realized that tar-derived oil was a beneficial roadbed sealer and binder (Wood, 1912). The City passed Ordinance 6715 in 1901, which specifically called for tar to be used in covering City streets (City of Portland Archives, 1901). The City’s use and placement of these materials on the roads is another potential source of PAHs. 3.1.5 Gas Holder Tank Sanborn maps and the figure supplied by ODEQ (Attachment 1) identify a gas holder located along the ATCS on the corner of NW Davis and NW 13th Avenue. The figure identifies operation from 1901 to 1908 when the ATCS was active. DEQ’s ECSI database previously documented this site by the identification number 5316 and listed this site as the Historic Portland Gas Co. Gas Holder Tank. Recent review of the ESCI database indicates this site is no longer listed. 3.2 Contaminants of Interest Identified in the Area The contaminants of interest identified in and around NW 9th Avenue and NW Lovejoy Street are PAHs, benzene, and other petroleum hydrocarbons. These contaminants have been reported in soil and groundwater as indicated on Figure 6 and Figure 7. 3.3 Pathways Reviewed The potential exposure pathways for the contaminants of interest identified in the area of interest to potentially adversely affect a human or ecological receptor are identified as air, soil, groundwater, stormwater, and sediment. Each of these potential pathways is discussed in more detail in Sections 4 and 5.

4 Data Review and Interpretation

Soil and groundwater data from near NW 9th Avenue and within and adjacent to the ATCS were compiled from historical sources and compared to RBCs in order to evaluate the nature and extent of contamination. Stormwater data from the 27-inch sewer, Tanner Creek CSS, and OF-11, as well as sediment data from near OF-11 were compiled and screened to evaluate whether a potential stormwater migration pathway to the Willamette River existed, and if so, whether it posed a risk to receptors in the river. 4.1 Soil There have been several extensive investigations on the private properties bordering NW 9th Avenue, as identified in Section 2.3. Sample data in this area have been generated primarily by studies of the Horse Barn, Former Hoyt Street Railyard, Centennial Mills, and the USPS P&DC sites. The reports containing this data include the following: • Remedial Investigation Report for the Burlington Northern Hoyt Street Site (RETEC, 1996) • Comprehensive Soil Remedial Investigation Report, River District Parcel 1 – Horse Barn Site (AMEC, 2002) • Interim Remedial Action Closure Report for Infrastructure Improvements Construction Project (AMEC, 2003) • Final Upland Source Control Evaluation Centennial Mills 1362 NW Naito Parkway (Hart Crowser, 2013) • Remedial Investigation Report USPS Portland P&DC (Arcadis, 2006) Soil data identified and evaluated in this investigation includes locations adjacent to the ATCS, within the ATCS, and along NW 9th Avenue from depths ranging from surface to approximately 15 ft bgs (the depths anticipated to be encountered by excavation workers). Sample locations are shown in Figure 6. The analytical results from 18 soil samples along NW 9th Avenue were compiled and screened against DEQ RBCs for soil ingestion, dermal contact, and inhalation in the excavation worker exposure scenario (Table 1). Samples were analyzed for PAHs, VOCs including benzene, ethylbenzene, toluene, and total xylene, and TPHs (diesel and heavy oil range). Three samples had exceedances of PAHs: HS9-Ext-W-W from 3.5 ft bgs, Worker-W-N-W from 0 to 10 ft bgs, and SS-3 from 12 ft bgs. All three samples exceeded the excavation worker RBCs for benzo(a)pyrene. One sample, Worker-W-N-W, also exceeded RBCs for benzo(a)anthracene, benzo(b)fluoranthene, and dibenzo(a,h)anthracene. Figure 6 indicates the approximate horizontal extent of soil exceeding the excavation worker RBC, as determined based on benzo(a)pyrene. Soil data from within or adjacent to the ATCS were found in the following investigation reports: • Remedial Action Closure Report Street Rights-of-Way (AMEC, 2007) provided data from samples collected along NW 9th Avenue and NW Marshall Street • Project Site Characterization Report: Lovejoy Ramp Demolition and Construction (Herrera Environmental Consultants, Inc., 1999) provided data from samples collected at the intersection of NW 9th Avenue and NW Lovejoy Street • Remedial Investigation Report USPS Portland P&DC (Arcadis, 2005) provided data from samples collected in and around the intersection of NW 9th Avenue and NW Lovejoy Street • Personal communication (Hafley, 2006) provided data from samples along NW 9th Avenue

13 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT 4.2 Groundwater Groundwater sample data were selected based on the depth of the sample. This evaluation was focused on the potential exposure of excavation workers and reviewed groundwater data collected from the depth interval that excavation workers would be expected to encounter (surface to approximately 15 ft bgs) (Table 3). These samples are considered representative of shallow groundwater conditions in this area. A total of 17 samples are included, all from different locations (Figure 7). The following investigations generated groundwater data adjacent to NW 9th Avenue or within or near the ATCS. • Final Upland Source Control Evaluation Centennial Mills (Hart Crowser, 2013) • Revised Final Annual Groundwater Monitoring Report -2008 Station Place Redevelopment Site (AMEC, 2009) • Comprehensive Groundwater Remedial Investigation Report, Horse Barn, River District Parcel 1 (AMEC, 2001) • Remedial Investigation Report USPS Portland P&DC (Arcadis, 2005) Groundwater data were analyzed for PAHs and VOCs and screened against the DEQ RBCs for groundwater in an excavation exposure scenario (DEQ, 2012). The only analytes identified to exceed excavation worker risk levels were naphthalene, benzo(a)pyrene, and dibenzo(a,h)anthracene. Water from inside the ATCS was sampled during manhole relocation at NW 9th Avenue at NW Lovejoy Street (O’Donovan, 2010). This sample is included in Table 2. The sample was analyzed for PAHs and screened against the DEQ RBCs for groundwater in an excavation. Two PAHs had exceedances of RBCs, benzo(a)anthracene and benzo(a)pyrene. Figure 7 indicates the approximate extent of groundwater exceeding the excavation worker RBC based on the results for benzo(a)pyrene. 4.3 Stormwater Stormwater data has been compiled and evaluated for the 27-inch sewer, Tanner Creek CSS, and OF-11 (Table 4, sample locations shown in Figure 8). A total of three sources of data were discovered: Centennial Mills SCE (Hart Crowser, 2013), Tanner Creek Water Quality Characterization Tech Memo (BES, 2011), and Tanner Creek Sewer Investigation and Evaluation (RETEC, 2004). Two of these sources contain data for the 27-inch sewer, including one event from 1990 with three sample locations (Hart Crowser, 2013) and two events from 2002, with three locations each (RETEC, 2004). Samples were evaluated for PAHs, VOCs, and TPHs. Values were screened against the DEQ RBCs for groundwater for the excavation worker scenario, Level II Aquatic screening level values (SLVs), and Joint Source Control Strategy (JSCS) SLVs. Several PAHs exceeded JSCS SLVs, including acenaphthene, acenaphthylene, anthracene, benzo(a)anthracene, benzo(a)pyrene, benzo(g,h,i)perylene, benzo(k)fluoranthene, chrysene, fluoranthene, fluorene, indeno(1,2,3-cd)pyrene, naphthalene, phenanthrene, and pyrene. Benzene, ethylbenzene, toluene, and diesel range hydrocarbons also exceeded SLVs in at least one sample. As part of the 2002 investigation, a risk assessment was performed on the stormwater data. Results of the assessment concluded that elevated PAHs were present in the stormwater but at sufficiently low levels that they do not exceed screening level values. Two of the sources contain data for stormwater within the Tanner Creek CSS, (RETEC, 2004 and BES, 2011) for a total of nine stormwater sampling events for the Tanner Creek CSS. Two events were conducted in 2002 at two locations each (RETEC, 2004). One sample was collected between OF-11 and the 27-inch sewer pipe invert and the other at the intersection of NW 10th Avenue and NW Lovejoy Street. These samples were evaluated for PAHs, VOCs, and TPHs. Seven sampling events were conducted by the City as part of the Tanner Creek water quality investigation at two locations (five events below the 27-inch sewer pipe invert and two events above the 27-inch sewer pipe invert) (BES, 2011). Samples were evaluated for PAH concentrations. Though this dataset also contained exceedances of PAH SLVs, the City concluded that the

14 SECTION 4. DATA REVIEW AND INTERPRETATION

pollutants detected appear to be at concentrations that do not pose serious risk to aquatic life. The City further stated that future stormwater quality is expected to remain constant or improve (BES, 2011). Two sampling events were conducted on stormwater discharging directly from OF-11, both in 2002 (RETEC, 2004). These samples were analyzed for PAHs, VOCs, and TPHs. One sample had exceedances of the JSCS SLVs for acenaphthene and pyrene. All other PAH concentrations were either nondetect or very low concentrations (RETEC, 2004). The water found in the back fill around the Tanner Creek CSS at the intersection of NW Pettygrove and NW Naito Parkway was sampled during four events in 2005-2006 by RETEC. The analytical results indicate the PAH compounds were below toxicity reference values. RETEC and DEQ concluded that the COIs in the soil and groundwater are not exacerbating water quality conditions in the Tanner Creek Sewer and do not appear to be contributing significant levels of contaminants to the Willamette River that would pose a risk to human or ecological receptors (Greenburg, 2008). This evaluation of the available data associated with the stormwater conveyance system discussed above indicates that stormwater discharging through the 27-inch sewer and OF-11 does not pose an unacceptable risk to human or ecological receptors in the Willamette River. 4.4 Sediment Five river sediment samples were analyzed from locations near OF-11 south of the former ATCS outfall, which was plugged by 1917 (Figure 9). All samples are considered surface sediment, collected from the water/ sediment interface to a maximum depth of 30 centimeters bgs. Two samples, located at river mile 11.4 along the west bank, were from the Portland Harbor Draft Remedial Investigation (LWG, 2011). The remaining three samples were found in the Centennial Mills SCE (Hart Crowser, 2013). These samples were collected in the general discharge zone of OF-11 (Table 5). All samples were analyzed for metals, PAHs, and polychlorinated biphenyl aroclors. One sample was analyzed for TPHs: diesel, motor oil, and gasoline ranges. The samples were screened against the Portland Harbor JSCS SLVs for sediment (revised July 2007) which are the more conservative of either the DEQ 2007 Bioaccumulative Sediment SLVs or MacDonald probable effect concentrations and other sediment quality values (MacDonald et al., 2000). Only two samples (T1S-09 and SED-1) contained metals elevated above JSCS SLVs. Both samples exceeded the SLV for mercury and one sample (SED-1) exceeded the SLV for lead. One sample, WR-PG-130, had slight exceedances of PAH SLVs for phenanthrene and indeno(1,2,3-cd)pyrene. In the evaluation of Portland Harbor data, no area of potential concern was identified adjacent to OF-11 or near the severed and plugged historic ATCS outfall to the north. This line of evidence together with the stormwater data demonstrate that stormwater discharging through the 27-inch sewer and OF-11 is not a risk to Willamette River. 4.5 Air The Remedial Investigation/Feasibility Study and risk assessment work that AMEC conducted for the Former Horse Barn/Station Place Redevelopment site on the northeast corner of NW 9th Avenue and NW Lovejoy Street indicated a potential risk for urban residents exposed to potential vapor intrusion of benzene into buildings constructed on this property. To mitigate this potential risk, the structures built on site incorporated a vapor extraction system. AMEC conducted a number of air monitoring events at these structures to determine the effectiveness of these systems. These air monitoring samples were collected at 1020 NW Lovejoy Street and 1044 Lovejoy Street. Samples reviewed for this document were collected from the vapor extraction system outlet, the intersection of NW 9th Avenue and NW Lovejoy Street, and the roof of the structure to represent “background” air conditions. The data from these sampling activities is summarized in Table 6 (AMEC, 2009a & b, 2010). Only three of the early samples taken from the vapor system exceed DEQ’s RBC for inhalation for the urban residential risk scenario. The three more-recent samples are well below the risk levels, indicating vapors that

15 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT may be released from contaminants of interest in the soil do not pose an unacceptable risk to residents, or any other receptors. The remaining sample results (Outdoor Roof and Outdoor Intersection of NW 9th & NW Lovejoy) indicate the “background” air in this area has similar or higher concentrations of contaminants of interest compared to what has been identified as potentially originating from contaminants in the soil.

5 Potential Risk Exposure Pathway Summary

Five risk exposure pathways were evaluated for this assessment: air, soil, groundwater, stormwater, and sediment. Each of these potential pathways was reviewed for potential exposure to receptors in the area around NW 9th Avenue and NW Lovejoy Street (see Figure 1), and the Willamette River (see Figure 9) as discussed below. 5.1 Air Soil vapor intrusion and ambient outdoor air were the two potential air exposure pathways identified in the environmental investigations on property located near the northeast corner of NW 9th Avenue and NW Lovejoy Street. Risk assessments conducted as part of the environmental investigations at the Former Horse Barn/Station Place Redevelopment site identified potential risk for occupational, residential, and urban residential exposure scenarios. With the implementation of DEQ-approved remedial actions, that site was able to address the potential of receptor exposure to potentially contaminated ambient outdoor air by applying a site cap consisting of clean soil cover and/or concrete or asphalt cover. The effectiveness of this remedy was monitored by periodic air sampling. The air monitoring conducted by AMEC indicates these remedial actions have addressed the potential air exposure in this area. A similar setting exists for the area of interest. The road surface at the intersection of NW 9th and NW Lovejoy Street is paved and maintained regularly by the City. The underground utility vaults are monitored and purged with fresh air whenever utility workers enter the vaults. Monitoring at adjacent properties (1020 & 1044 NW Lovejoy Street) has shown no potential air exposure exceedances related to the contaminants of interest in the soil. 5.2 Soil Soil containing elevated levels of contaminants of interest is located beneath, and is thus covered by, NW 9th Avenue, surrounding buildings, and the public sidewalk. These barriers prevent soil contact with potential receptors (human and ecological) and prevent migration of contaminants. The only likely scenario where contact with soil may occur is in the excavation worker scenario. Contaminant concentrations in shallow soil (above 15 ft bgs) were compared to DEQ RBCs for the excavation worker scenario and found to have exceedances of benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene, and dibenzo(a,h)anthracene (Tables 1 and 2). 5.3 Groundwater Groundwater in the area of interest as shown in Figure 1 has been thoroughly investigated from the properties adjacent to NW 9th Avenue (including samples collected under NW 9th Avenue) and Records of Decision are in place (USPS Site, Horse Barn Site, and Former Hoyt Street Railyard). In general, the investigations and Records of Decision found that there is no current or reasonably likely future use of the shallow groundwater in the area and that the flow is limited by the fine-grained nature of the soil making up the shallow aquifer. The only risk identified was to excavation workers who may be exposed to the shallow groundwater. Institutional controls were put in place on surrounding properties including groundwater management plans and worker notification and protection plans. Contaminant concentrations in shallow groundwater in the area and water in the ATCS were compared to DEQ RBCs for the excavation worker scenario and found to have exceedances of benzo(a)pyrene, dibenzo(a,h)anthracene, and benzo(a)anthracene near NW 9th Avenue, and benzo(a)pyrene and benzo(a)anthracene for water in the ATCS (Table 3). This investigation focused on potential groundwater exposure to a depth of approximately 15 ft bgs.

17 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT 5.4 Stormwater There is not a stormwater migration pathway from the ATCS to the Willamette River. The ATCS was reported to be abandoned by sealing the outfall with concrete and filling the pipeline with sand. In addition, the ATCS was severed at NW Front Avenue when the Tanner Creek CSS was constructed between 1915 and 1917. Voids that were encountered more recently in the ATCS were filled with CDF. This was conducted as part of the construction at NW Marshall in 2002, in the northern portion of the ATCS in 2009, and during stormwater pipeline work in the intersection of NW 9th Avenue and NW Lovejoy Street in 2010. Figure 1 shows the locations of the CDF placement. There are places in the 27-inch Sewer where groundwater can enter and mix with stormwater (RETEC, 2004); however, the stormwater data from the 27-inch Sewer and Tanner Creek CSS, which drain this area, shows that PAHs are either nondetect or only detected in low concentrations below established RBCs for aquatic species (BES, 2011; RETEC, 2004; and Greenburg, 2008) indicating the stormwater reaching the Willamette River through OF-11 does not pose an unreasonable risk to ecological receptors (see Section 4.3). 5.5 Sediment The closest sediment to NW 9th Avenue and NW Lovejoy Street that would support potential ecological receptors is about 1,500 ft distant in the Willamette River at the discharge point of OF-11. Analytical data from sediment samples collected adjacent to OF-11 and the former ATCS outfall indicate the concentrations of contaminants are not likely to pose an unacceptable risk to potential ecological or human receptors (see Section 4.4).

6 Findings and Conclusions

Evaluation of the historical data within and adjacent to the ATCS along NW 9th Avenue yielded the following: 1. Multiple potential sources of contaminants of potential interest may have adversely affected the identified area of interest. These potential sources include but are not limited to the former MGP, former nearby asphalt plant and steel foundry, former leaking USTs and ASTs in the vicinity, as well as historical City road-coating practices. 2. Soil and groundwater data from near NW 9th Avenue as well as within and adjacent to the ATCS were compiled and compared to risk-based concentrations. Concentrations of contaminants of interest were found in the soil and groundwater in the area that exceed risk-based concentrations for the unprotected excavation worker scenario as shown in Figures 6 and 7. However, the City of Portland has policies and procedures in place to eliminate this risk pathway by requiring proper protection for excavation workers in this area. 3. Stormwater data from the 27-inch sewer, Tanner Creek CSS, and OF-11 as well as sediment data from near OF-11 were compiled and screened to determine if the stormwater pathway to the Willamette River poses a risk to potential receptors in the river. The data evaluated in this investigation indicates that stormwater in the 27-inch Sewer, Tanner Creek CSS, and the ATCS is not a source of contaminants of interest at concentrations that would pose an unacceptable risk to potential ecological receptors in the Willamette River. Consistent with these findings, in the evaluation of Portland Harbor data, no area of potential concern was identified adjacent to OF-11 or near the severed and plugged historic ATCS outfall to the north. Underground utility lines in this area do not provide a significant preferential pathway for contaminants of interest to migrate to the Willamette River. 4. Air monitoring data from properties near NW 9th Avenue and NW Lovejoy were compiled and compared to risk-based concentrations. This data indicates the street and sidewalk pavement are effective in eliminating vapor intrusion as a potential exposure pathway. These findings demonstrate that the only potential exposure pathway is to unprotected excavation workers via direct contact with soil or groundwater. This risk pathway is addressed by the City’s environmental practice in place to evaluate each construction project involving excavation under City streets or sidewalks for environmental considerations. When the City plans a construction project, an environmental review of surrounding properties is conducted. If this review identifies a feature of potential environmental concern, environmental sampling is conducted to facilitate waste stream characterization and facilitate worker safety practices. These practices ensure a City excavation project in this area will trigger an environmental review to identify potential environmental and potential worker risks. The nature of contamination and potential for exposure to such contamination in and around the ATCS is similar to properties surrounding NW 9th Avenue and NW Lovejoy Street that are identified DEQ ECSI sites with residual contamination left in place (Former Hoyt Street Railyard – 1080; Horse Barn – 2407; USPS – 2183; and Pearl Block – 4960). The approximate area of recommended environmental monitoring for excavation work (i.e., implementation of proper protocol based on existing data) is identified in DEQ’s ECSI database as site 5328 and presented in Figure 10. This report documents the known contamination in this area and identifies the approximate extent of the area where soil and groundwater may exceed the excavation worker RBCs (Figure 6, 7, and 10) and the area recommended for continued environmental monitoring should excavation work be required (Figure 10). When the City conducts its environmental review, it will identify this area as having potential soil and groundwater contamination that could pose unacceptable risk to unprotected excavation workers. As a result, the City will allow only Occupational Safety and Health Administration 40-hour trained workers to work in this area, as is true of all areas of known contamination. This evaluation demonstrates that contamination found near the intersection of NW 9th Avenue and NW Lovejoy Street does not pose an unacceptable risk to human and ecological receptors because current

19 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT controls are effective at eliminating or reducing potential risks to human and ecological receptors associated with potential exposure to soil or groundwater. As stated in the Voluntary Letter Agreement between PTRR and DEQ, this document concludes PTRR’s obligations stated in that agreement and no further characterization or controls are needed. PTRR requests DEQ update the appropriate environmental cleanup files indicating no further investigation or other work is required of Portland Terminal Railroad Company.

7 References

AGRA. 1996. Draft Comprehensive RI Report, Union Station Parcel B South, Portland, Oregon. September 1996. AMEC Earth & Environmental (AMEC). 2001. Comprehensive Groundwater Remedial Investigation Report, Horse Barn, River District Parcel 1, Portland, Oregon. AMEC. 2002. Comprehensive Soil Remedial Investigation Report, River District Parcel 1 – Horse Barn Site, NW 9th Avenue and Lovejoy Street, Portland, Oregon. DEQ File No. 2407. April 2002. AMEC. 2003. Interim Remedial Action Closure Report for Infrastructure Improvements Construction Project. AMEC. 2007. Remedial Action Closure Report, Street Rights-of-Way, Station Place Redevelopment Site, Portland, Oregon. AMEC. 2009. Revised Final Annual Groundwater Monitoring Report-2008, Station Place Redevelopment Site, Portland, Oregon. AMEC. 2009a. 2008 Annual Indoor Air Monitoring Report The Tower at Station Place Station Place Redevelopment Site Portland, Oregon, January 2009. AMEC. 2009b. Pre-Occupancy Indoor Air Monitoring Report Station Place Redevelopment Site, Lot2 Ziba Headquarters Office Building Portland, Oregon. September 2009. AMEC. 2010. 2010 Indoor Air Monitoring Report Station Place Redevelopment Site, Lot 2 Ziba Headquarters Office Building Portland, Oregon. September 2010. Arcadis. 2005. Remedial Investigation Report, USPS P&DC 715 NW Hoyt Street Portland, Oregon 97208. June 29. Arcadis. 2006. Final Remedial Investigation Report USPS Portland P&DC. April 21. CH2M HILL. 2011. Abandoned Tanner Creek Sewer Investigation Phase 1 Work Plan. Technical memorandum from Ken Shump of CH2M HILL to Dan Hafley of Oregon DEQ. March 4, 2011. City of Portland Archives. 1901. City of Portland Ordinance 6715. Road surface specifications. City of Portland Bureau of Environmental Services (BES). 2011. Tanner Creek Water Quality Characterization. June 2011. Exponent, Inc. 2012. Final Closure Report. USPS Portland P&DC 715 Northwest Hoyt Street Portland OR 97208. April 2012. Greenburg, M. 2008. Memorandum to DEQ File for Hoyt Street Railyard – ECSI #1080, Satisfactory Completion of Tanner Creek Sewer Investigation. May 1, 2008. Hafley, D. 2006. Personal communication with Dan Hafley, Oregon DEQ, regarding sampling conducted by Portland Development Commission at the Centennial Mills site, Portland, Oregon. Hart Crowser. 2013. Final Upland Source Control Evaluation Centennial Mills 1362 NW Naito Parkway. March 21, 2013. Herrera Environmental Consultants, Inc. 1999. Project Site Characterization Report: Lovejoy Ramp Demolition and Construction. Integral. 2013. 2012 Groundwater Monitoring Report, Former Hoyt Street Railyard. January 29, 2013.

21 FINAL ABANDONED TANNER CREEK SEWER AND 9TH AND LOVEJOY STREET DATA INVESTIGATION SUMMARY AND SOURCE CONTROL EVALUATION REPORT LWG. 2011. Portland Harbor Remedial Investigation Report Draft prepared for The Lower Willamette Group by Integral Consulting Inc., Windward Environmental LLC, Kennedy/Jenks Consultants, Anchor QEA, LLC. 2011. LWG. 2012. Portland Harbor RI/FS Draft Feasibility Study prepared for The Lower Willamette Group by Anchor QEA, LLC., Windward Environmental LLC, Kennedy/Jenks Consultants, Integral Consulting Inc, 2012. MacDonald, D.D., C.G. Ingersoll, and T.A. Berger. 2000. Development and Evaluation of Consensus-Based Sediment Quality Guidelines for Freshwater Ecosystems. Environmental Contamination and Toxicity 39: 20-31. O’Donovan, J. 2010. Personal communication with John O’Donovan, City of Portland Bureau of Environmental Services, regarding sample results for water sample collected from the abandoned Tanner Creek sewer in March 2010 from a manhole excavation. Oregon Department of Environmental Quality (DEQ). 2000. Record of Decision. Selected Remedial Action for Hoyt Street Railyard Portland, Oregon. December 15, 2000. DEQ. 2003. Record of Decision. Selected onsite Remedial Action for the Union Station – Horse Barn Site Portland, Oregon. May 2003. DEQ. 2010. Letter from Dan Hafley of DEQ to Russ Hullihan of Portland Terminal Railroad Company regarding Voluntary Agreement, 9th and Lovejoy Contamination. August 19, 2010. DEQ. 2012. Environmental Contamination Site Information Database for Side I.D. 5328, Abandoned Tanner Creek Sewer. www.deq.state.or.us/lq/ECSI/ecsidetail.asp?seqnbr=5328. Accessed May 2012. DEQ. 2014. Memorandum from Daniel Hafley of DEQ to Rich Muza dn Kristine Koch of EPA regarding Source Control Decision, Centennial Mills, ECSI #5136. March 7, 2014. RETEC. 1996. Remedial Investigation Report for the Burlington Northern Hoyt Street Site. October 1996. RETEC. 2004. Tanner Creek Sewer Investigation and Evaluation. Former Hoyt Street Railyard, Portland Oregon. February 2, 2004. Wood, Francis. 1912. Modern Road Construction. A Practical Treatise for the use of Engineers, Students, Members of Local Authorities, Etc. Published in London by Charles Griffin and Company, Limited Published in Philadelphia: J.B. Lippincott Company. 1912.

Tables

TABLE 1 Analytical Summary of Soil Samples along NW 9th Avenue Portland Terminal Railroad Company Portland, OR Sample location 2RISB-01 2RISB-5 3HB-1 3HB-2 3HB-4 3HB-7 3HB-11 3HB-43 3HB-29 3HB-47 4HS9-Ext-W-W 4Worker-W-N-W Depth (ft) 15 6 10 2 5 9 10 10 11 4 12 4 11 20 3.5 0-10 Parameter Units Date 12/15/95 12/15/95 11/2/99 11/2/99 11/2/99 11/2/99 11/2/99 11/4/99 11/4/99 6/21/00 6/21/00 11/3/99 11/3/99 6/19/00 12/4/02 11/5/02 1 PAHs DEQ RBCs acenaphthylene ug/kg -- 6,700 U 11 U 10 U 62 U 10 U 10 U 10 U 160 4,400 2,800 11 U 73 1,200 51,000 100,000 acenaphthene ug/kg 520,000,000 24,000 J 11 U 10 U 62 U 10 U 10 U 10 U 510 2,900 U 40,000 11 U 55 U 380 96,000 140,000 fluorene ug/kg 340,000,000 23,000 J 11 U 10 U 62 U 10 U 10 U 10 U 1,500 2,900 U 16,000 11 U 55 U 1,000 51,000 190,000 phenanthrene ug/kg -- 130,000 J 11 U 14 360 10 U 10 U 10 U 2,500 7,700 79,000 45 190 3,600 610,000 2,700,000 anthracene ug/kg -- 19,000 J 11 U 10 U 66 10 U 10 U 10 U 110 5,200 17,000 11 U 55 U 960 180,000 400,000 fluoranthene ug/kg 250,000,000 38,000 J 11 U 16 350 10 U 10 U 12 350 8,200 31,000 39 170 1,000 480,000 150,000 pyrene ug/kg -- 77,000 J 11 U 19 250 10 U 10 U 10 U 360 20,000 52,000 62 220 1,700 740,000 2,100,000 benzo(a)anthracene ug/kg 590,000 18,000 J 11 U 10 U 140 10 U 10 U 10 U 140 12,000 13,000 21 96 600 280,000 1,000,000 chrysene ug/kg 57,000,000 24,000 J 11 U 10 U 150 10 U 10 U 10 U 130 16,000 12,000 17 120 550 260,000 900,000 benzo(b)fluoranthene ug/kg 590,000 9,000 J 11 U 13 200 10 U 10 U 10 U 140 17,000 9,600 23 110 390 190,000 790,000 benzo(k)fluoranthene ug/kg 5,900,000 14,000 J 11 U 10 U 62 U 10 U 10 U 10 U 56 4,800 3,200 11 U 55 U 130 220,000 700,000 benzo(a)pyrene ug/kg 59,000 20,000 J 11 U 12 130 10 U 10 U 10 U 130 26,000 13,000 30 110 570 490,000 1,600,000 dibenzo(a,h)anthracene ug/kg 59,000 6,700 U 11 U 10 U 62 U 10 U 10 U 10 U 19 U 3,700 1,200 11 U 55 U 62 10,000 U 320,000 benzo(g,h,i)perylene ug/kg -- 6,700 U 11 U 13 110 10 U 10 U 10 U 75 20,000 6,000 19 86 200 440,000 1,100,000 indeno(1,2,3-cd)pyrene ug/kg 590,000 6,700 U 11 U 10 U 93 10 U 10 U 10 U 61 10,000 4,400 12 55 U 170 280,000 870,000 naphthalene ug/kg 16,000,000 240,000 J 17 10 U 180 10 U 11 10 U 340 2,900 J 180,000 32 240 13,000 150,000 340,000 VOCs benzene ug/kg 9,500,000 420 ethylbenzene ug/kg 44,000,000 23,000 toluene ug/kg 680,000,000 340 xylenes (total) ug/kg 540,000,000 6,800 TPH diesel range mg/kg -- 3,900 25 U heavy oil range mg/kg -- 940 50 U Notes: -- = no established RBC 1 DEQ risk-based concentration (RBC) for soil ingestion, dermal contact, and inhalation in the excavation worker exposure senario, last revised June 7, 2012. (DEQ, 2012) 2 Remedial Investigation Report for the Burlington Northern Hoyt Street Railyard (RETEC, 1996) 3 Horse Barn Site Remedial Investigation Report (AMEC, 2002) 4 Interim Remedial Action Closure Report for Infrastructure Improvements Construction Project (AMEC, 2003) 5 Centennial Mills Final Upland Source Control Evaluation (HartCrowser, 2013) 6 Remedial Investigation Report USPS Portland P&DC (Arcadis, 2005) J = estimated concentration - analyte detected but below instrument calibration. mg/kg = milligrams per kilogram PAHs = polynuclear aromatic hydrocarbons Shaded indicates the dectected analyte that exceeds the screening value. TPH = total petroleum hydrocarbons U = nondetect ug/kg = micrograms per kilogram VOCs = volatile organic carbons

Page 1 of 9 TABLE 1 Analytical Summary of Soil Samples along NW 9th Avenue Portland Terminal Railroad Company Portland, OR Sample location 5MW-2 6SS-3 Depth (ft) 14 0 12 Parameter Units Date 6/3/10 6/26/05 6/26/05 1 PAHs DEQ RBCs acenaphthylene ug/kg -- 23 U 168 U 27,200 acenaphthene ug/kg 520,000,000 20 U 168 U 248,000 fluorene ug/kg 340,000,000 24 168 U 245,000 phenanthrene ug/kg -- 87 262 950,000 anthracene ug/kg -- 25 168 U 286,000 fluoranthene ug/kg 250,000,000 92 357 389,000 pyrene ug/kg -- 94 349 717,000 benzo(a)anthracene ug/kg 590,000 32 175 223,000 chrysene ug/kg 57,000,000 41 276 236,000 benzo(b)fluoranthene ug/kg 590,000 50 256 80,500 benzo(k)fluoranthene ug/kg 5,900,000 50 168 104,000 benzo(a)pyrene ug/kg 59,000 28 205 184,000 dibenzo(a,h)anthracene ug/kg 59,000 10 168 U 29,800 benzo(g,h,i)perylene ug/kg -- 33 263 99,000 indeno(1,2,3-cd)pyrene ug/kg 590,000 25 212 77,900 naphthalene ug/kg 16,000,000 94 168 U 188,000 VOCs benzene ug/kg 9,500,000 8 U ethylbenzene ug/kg 44,000,000 34 U toluene ug/kg 680,000,000 34 U xylenes (total) ug/kg 540,000,000 67 U TPH diesel range mg/kg -- 76 J 94 549 heavy oil range mg/kg -- 54 308 476 Notes: -- = no established RBC 1 DEQ risk-based concentration (RBC) for soil ingestion, dermal contact, and inhalation in the excavation worker exposure senario, last revised June 7, 2012. (DEQ, 2012) 2 Remedial Investigation Report for the Burlington Northern Hoyt Street Railyard (RETEC, 1996) 3 Horse Barn Site Remedial Investigation Report (AMEC, 2002) 4 Interim Remedial Action Closure Report for Infrastructure Improvements Construction Project (AMEC, 2003) 5 Centennial Mills Final Upland Source Control Evaluation (HartCrowser, 2013) 6 Remedial Investigation Report USPS Portland P&DC (Arcadis, 2005) J = estimated concentration - analyte detected but below instrument calibration. mg/kg = milligrams per kilogram PAHs = polynuclear aromatic hydrocarbons Shaded indicates the dectected analyte that exceeds the screening value. TPH = total petroleum hydrocarbons U = nondetect ug/kg = micrograms per kilogram VOCs = volatile organic carbons

Page 2 of 9 TABLE 2 Analytical Summary of Soil and Water Samples from within or adjacent to ATCS Portland Terminal Railroad Company Portland, OR Sample # (keyed to Figure 2) 1 2 3 4 5 Depth (ft bgs) 9 13 inside top of ATCS 1' -2' below top of ATCS Water Sample Location Inside Outside Inside Inside Inside Units Concentration in ug/kg (ppb) ppb (ug/L) 4Trench 1 soil sample 5TC1 soil sample from 6TC3 soil sample from Parameter 1DEQ RBCs 3Centennial Mills TCS-1 from outside ATCS inside ATCS inside ATCS 2DEQ RBCs 79th & Lovejoy Naphthalene 16,000,000 3,240 34,700 16,100 5,400 500 0.6 Acenaphthylene -- 669 2,530 29,200 5,560 -- 23.7 Acenaphthene 520,000,000 640 22,100 260,000 45,000 -- 31.1 Fluorene 340,000,000 1,310 14,600 197,000 32,700 -- 13.1 Anthracene -- 1,920 16,300 297,000 46,900 -- 10.6 Phenanthrene -- 7,000 67,600 1,000,000 145,000 -- 1 Fluoranthene 250,000,000 5,390 21,000 494,000 68,100 -- 30.3 Pyrene -- 7,140 39,400 827,000 118,000 -- 78.8 Benzo(a)anthracene 590,000 1,840 11,200 234,000 36,600 9.1 23.6 Chrysene 59,000,000 2,240 11,700 254,000 37,700 -- 8.3 Benzo(a)pyrene 59,000 1,740 11,600 231,000 37,100 0.53 29.1 Benzo(b)fluoranthene 590,000 133 5,370 89,700 15,300 -- 32.6 Benzo(k)fluoranthene 5,900,000 133 6,630 154,000 21,800 -- 10 Benzo(g,h,i)perylene -- 1,340 5,970 112,000 17,900 -- 26.9 Indeno(1,2,3-cd)pyrene 590,000 1,070 4,500 83,200 13,800 -- 20.2 Dibenzo(a,h)anthracene 59,000 133 1,530 28,500 4,770 0.21 5 Total PAHs 35,937 276,730 4,306,700 651,630 129,670 Notes: -- = no established RBC 1 DEQ risk-based concentration (RBC) for soil ingestion, dermal contact, and inhalation in the excavation worker exposure scenario, last revised June 7, 2012. (DEQ, 2012) 2 DEQ risk-based concentration (RBC) for groundwater in an excavation exposure scenario, last revised June 7, 2012. (DEQ, 2012) 3 Material found inside ATCS. Upland Source Control Evaluation Centennial Mills (HartCrowser, 2013). Table 12 Sample ID TCS-1A (inside) collected 6/24/09. 4 Backfill material found surrounding ATCS at NW 9th Ave and NW Marshall St. Remedial Action Closure Report Street Right of Ways (AMEC, 2007). Sample ID Trench 1 collected 10/30/02. 5 Material found inside ATCS NW 9th Ave and NW Marshall St. Remedial Action Closure Report Street Right of Ways (AMEC, 2007). Sample ID Tanner Creek 1 collected 10/30/02. 6 Material found inside ATCS NW 9th Ave and NW Marshall St. Remedial Action Closure Report Street Right of Ways (AMEC, 2007). Sample ID Tanner Creek 2 collected 10/30/02. 7 Sample collected by City of Portland from manhole excavation being relocated for Portland Street Car 2010 (O’Donovan, 2010). ft bgs = feet below ground surface PAHs = polynuclear aromatic hydrocarbons ppb = parts per billion Shaded indicates the detected analyte exceeds the screening value. ug/kg = micrograms per kilogram ug/L = micrograms per Liter

Page 3 of 9 TABLE 3 Analytical Summary of Groundwater Samples along NW 9th Avenue Portland Terminal Railroad Company Portland, OR Sample Location 2GP-19 2GP-20 2RASB-13SED 2GP-13 2GP-14 3HB8-GW 3HB-17 3HB29-GW 3HBMW2 3HBMW3 3HBMW5 3HBMW6 3HBMW6A Parameter Units Sample Date 5/19/11 5/19/11 11/1/02 5/18/11 5/18/11 11/2/99 11/3/99 11/3/99 3/9/01 3/9/01 3/9/01 8/10/00 3/9/01 1 PAH DEQ RBCs naphthalene ug/L 500 0.0302 J 0.0307 J 0.8 U 0.971 U 0.194 U 0.1 U 0.1 U 26.0 0.5 U 0.1 U 18.9 2,300.0 181.0 acenaphthylene ug/L -- 0.00943 U 0.0099 U 0.1 U 1.94 U 0.315 J 0.1 U 0.1 U 1.1 0.1 U 0.1 U 0.35 3.2 7.69 acenaphthene ug/L -- 0.00943 U 0.0099 U 0.1 U 1.94 U 1.24 0.1 U 0.1 U 55 2.87 0.1 U 3.43 130 229 fluorene ug/L -- 0.0239 0.0147 J 0.1 U 1.94 U 2.48 0.1 U 0.1 U 11 2.25 0.1 U 0.311 26 70.6 phenanthrene ug/L -- 0.0606 0.0332 0.1 U 0.485 U 0.743 0.1 U 0.1 U 4.5 5.28 0.1 U 0.1 U 45 41 anthracene ug/L -- 0.0112 J 0.0099 U 0.1 U 1.94 U 0.315 J 0.1 U 0.1 U 1.9 0.212 0.1 U 0.108 0.1 U 18.8 fluoranthene ug/L -- 0.0134 J 0.0144 J 0.1 U 1.27 0.391 0.1 U 0.1 U 0.8 0.612 0.1 U 0.1 U 3.7 7.45 pyrene ug/L -- 0.0105 J 0.0124 J 0.1 U 1.37 0.487 0.1 U 0.1 U 1 0.874 0.1 U 0.104 0.1 U 10.7 benzo(a)anthracene ug/L 9.1 0.00943 U 0.013 J 0.1 U 0.603 J 0.193 J 0.1 U 0.1 U 0.2 0.1 U 0.1 U 0.1 U 0.5 5 U chrysene ug/L -- 0.00943 U 0.0099 U 0.1 U 0.759 J 0.2 0.1 U 0.1 U 0.1 0.1 U 0.1 U 0.1 U 0.5 5 U benzo(b)fluoranthene ug/L -- 0.00943 U 0.0135 J 0.1 U 0.728 U 0.146 U 0.1 U 0.1 U 0.2 0.1 U 0.1 U 0.1 U 0.3 5 U benzo(k)fluoranthene ug/L -- 0.00943 U 0.0099 U 0.1 U 0.728 U 0.146 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 5 U benzo(a)pyrene ug/L 0.53 0.00943 U 0.0099 U 0.1 U 0.728 U 0.194 J 0.1 U 0.1 U 0.3 0.1 U 0.1 U 0.1 U 0.4 5 U indeno(1,2,3-cd)pyrene ug/L -- 0.00943 U 0.0099 U 0.1 U 0.485 U 0.0971 U 0.1 U 0.1 U 0.1 0.1 U 0.1 U 0.1 U 0.2 5 U dibenzo(a,h)anthracene ug/L 0.21 0.00943 U 0.0099 U 0.1 U 0.485 U 0.0971 U 0.1 U 0.1 U 0.1 U 0.2 U 0.2 U 0.2 U 0.1 U 10 U benzo(g,h,i)perylene ug/L -- 0.00943 U 0.0099 U 0.1 U 0.485 U 0.0971 U 0.1 U 0.1 U 0.2 0.1 U 0.1 U 0.1 U 0.2 5 U VOCs benzene ug/L 1,700 0.5 U 0.125 U 0.18 J 1 U 1 U 400 1 U 1 U 180 2500 1100 ethylbenzene ug/L 4,400 0.5 U 0.25 U 0.25 U 1 U 1 U 2.49 1 U 1 U 9.4 1300 320 toluene ug/L 210,000 0.5 U 0.52 J 0.68 J 1 U 1 U 1 U 1 U 1 U 1.1 24 14 xylenes (total) ug/L 23,000 1 U 0.5 U 0.5 U 3 U 3 U 2.83 3 U 3 U 23 329 130 Notes: Shaded indicates the dectected analyte exceeds the screening value. -- = no established RBC 1 DEQ risk-based concentration (RBC) for groundwater in an excavation exposure scenario, last revised June 7, 2012. (DEQ, 2012) 2 Centennial Mills Final Upland Source Control Evaluation (Hart Crowser, 2013) 3 Comprehensive Soil and Groundwater Remedial Investigation -2001 Horse Barn (AMEC, 2001) 4 Remedial Investigation Report USPS Portland P&DC (Arcadis, 2005) J = estimated concentration - analyte detected but below instrument calibration. PAHs = polynuclear aromatic hydrocarbons U = nondetect ug/L = micrograms per Liter VOCs = volatile organic carbons

Page 4 of 9 TABLE 3 Analytical Summary of Groundwater Samples along NW 9th Avenue Portland Terminal Railroad Company Portland, OR Sample Location 3HBMW7 3HBMW8 4MW-3 4SS-2 Parameter Units Sample Date 3/9/01 8/11/00 6/26/05 6/26/05 1 PAH DEQ RBCs naphthalene ug/L 500 0.1 U 0.1 U 1,070 24.5 acenaphthylene ug/L -- 0.1 U 0.1 U 2 U 2.76 acenaphthene ug/L -- 0.1 U 0.1 U 104 17.3 fluorene ug/L -- 0.1 U 0.1 U 42.9 10.8 phenanthrene ug/L -- 0.1 U 0.1 U 62.2 12.9 anthracene ug/L -- 0.1 U 0.1 U 6.73 4.54 fluoranthene ug/L -- 0.1 U 0.1 U 3.81 11.2 pyrene ug/L -- 0.1 U 0.1 U 7.24 19.8 benzo(a)anthracene ug/L 9.1 0.1 U 0.1 U 0.41 6.25 chrysene ug/L -- 0.1 U 0.1 U 0.483 7.5 benzo(b)fluoranthene ug/L -- 0.1 U 0.1 U 0.2 U 4.02 benzo(k)fluoranthene ug/L -- 0.1 U 0.1 U 0.2 U 4.61 benzo(a)pyrene ug/L 0.53 0.1 U 0.1 U 0.2 U 7.52 indeno(1,2,3-cd)pyrene ug/L -- 0.1 U 0.1 U 0.2 U 4.56 dibenzo(a,h)anthracene ug/L 0.21 0.2 U 0.1 U 0.2 U 1.52 benzo(g,h,i)perylene ug/L -- 0.1 U 0.1 U 0.2 U 7.11 VOCs benzene ug/L 1,700 0.5 U 1 U ethylbenzene ug/L 4,400 0.5 U 1 U toluene ug/L 210,000 0.5 U 1 U xylenes (total) ug/L 23,000 0.5 U 3 U Notes: Shaded indicates the dectected analyte exceeds the screening value. -- = no established RBC 1 DEQ risk-based concentration (RBC) for groundwater in an excavation exposure scenario, last revised June 7, 2012. (DEQ, 2012) 2 Centennial Mills Final Upland Source Control Evaluation (Hart Crowser, 2013) 3 Comprehensive Soil and Groundwater Remedial Investigation -2001 Horse Barn (AMEC, 2001) 4 Remedial Investigation Report USPS Portland P&DC (Arcadis, 2005) J = estimated concentration - analyte detected but below instrument calibration. PAHs = polynuclear aromatic hydrocarbons U = nondetect ug/L = micrograms per Liter VOCs = volatile organic carbons

Page 5 of 9 TABLE 4 Analytical Summary of Stormwater Samples for the 27 inch Storm Sewer, Tanner Creek CSS, and Outfall 11 Portland Terminal Railroad Company Portland, OR 427" Storm Sewer 527" Storm Sewer Sample Location RASS-5 RASS-5 Dup RASS-6 RASS-7 RASS-5 RASS-6 RASS-7 SS-2 SS-4 SS-3 Constituent Units Sample Date 12/31/02 12/31/02 12/31/02 12/31/02 10/30/02 10/30/02 10/30/02 1DEQ 2Level II 3JSCS PAHs RBCs Aquatic SLVs Table 3-1 acenaphthene ug/L -- 520 0.2 3.97 3.97 4.75 7.93 0.75 40.9 0.61 0.852 17 8.2 acenaphthylene ug/L -- -- 0.2 0.15 0.15 0.15 0.2 0.1 U 1 0.1 U 0.2 U 0.2 U 0.2 U anthracene ug/L -- 13 0.2 0.355 0.355 0.413 0.755 0.1 U 2.98 0.1 U 0.051 B 0.01 U 1 B benzo(a)anthracene ug/L 9.1 0.027 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.05 0.17 0.1 U 0.01 U 0.01 U 4 benzo(a)pyrene ug/L 0.53 0.014 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.01 U 2.5 0.01 U benzo(b)fluoranthene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.01 U 0.01 U 0.01 U benzo(g,h,i)perylene ug/L -- -- 0.2 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.02 U 3.7 0.02 U benzo(k)fluoranthene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.01 U 2.4 0.01 U chrysene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.11 0.17 0.1 U 0.018 0.01 U 0.01 U dibenzo(a,h)anthracene ug/L 0.21 -- 0.018 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.01 U 0.01 U 0.01 U fluoranthene ug/L -- 6.2 0.2 0.405 0.405 0.425 0.726 0.51 2.26 0.59 0.01 U 730 66 fluorene ug/L -- 3.9 0.2 2.05 2.05 2.47 3.05 0.33 8.24 0.1 U 0.15 120 15 indeno(1,2,3-cd)pyrene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.02 U 1.4 0.02 U naphthalene ug/L 500 620 0.2 0.47 0.47 0.531 0.979 0.2 U 1.5 0.1 U 0.05 U 0.05 U 1.3 phenanthrene ug/L -- 6.3 0.2 0.695 0.695 0.502 2.05 0.1 U 3.44 0.1 U 0.076 210 21 pyrene ug/L -- -- 0.2 0.557 0.557 0.571 0.999 1.04 3.27 1.14 0.13 210 17 Total PAHs ug/L 9 9 9.81 16.69 2.79 63.9 2.34 1.28 1297 134 VOCs benzene ug/L 1,700 130 1.2 4.69 4.74 28.6 12.4 0.5 U 56.9 1.44 24 20 1 U ethylbenzene ug/L 4,400 7.3 7.3 1.64 1.65 9.57 3.81 0.5 U 0.5 U 0.5 U 8 20 1 U toluene ug/L 210,000 9.8 9.8 0.5 U 0.5 U 0.5 U 0.5 U 0.5 U 14.4 0.66 1 U 20 U 1 U total xylene ug/L 23,000 -- 200 1 U 1 U 2.82 1.91 1 U 2.6 1 U 2 20 U 1 U TPH diesel range ug/L 360 -- -- 382 J 250 U 250 U 304 J 250 U 250 U 250 U motor oil range ug/L 1,100 -- -- 500 U 500 U 500 U 500 U 500 U 500 U 500 U gasoline range ug/L 420 -- -- 90.5 91 168 122 80 U 174 80 Notes: 1 DEQ risk-based concentrations (RBC) for groundwater in an excavation exposure scenario, last revised June 7, 2012. (DEQ, 2012) -- = no established screening value 2 DEQ Level II Screening Level Values. Table 1, Surface Water, Aquatic. 3 Portland Harbor Joint Source Control Strategy (JSCS) Screening levels taken from Table 3-1 Screening level Values for Stormwater, Revised 7/16/07. (DEQ, 2007) 4 Tanner Creek Sewer Investigation and Evaluation, Former Hoyt Street Railyard (RETEC, 2004) 5 Centennial Mills SCE (Hart Crowser, 2013) 6 Tanner Creek Water Quality Characterization Tech Memo (City of Portland BES, 2011) J = estimated concentration - analyte detected but below instrument calibration. PAHs = polynuclear aromatic hydrocarbons Shaded indicates the dectected analyte that exceeds the screening value. TPH = total petroleum hydrocarbons U = nondetect ug/L = micrograms per Liter VOCs = volatile organic carbons

Page 6 of 9 TABLE 4 Analytical Summary of Stormwater Samples for the 27 inch Storm Sewer, Tanner Creek CSS, and Outfall 11 Portland Terminal Railroad Company Portland, OR Tanner Creek CSO (below 27") Tanner Creek CSO (above 27") Tanner Creek CSO Outfall 11 (below 27") Sample Location TC16 TC26 RASS-14 Constituent Units Sample Date 1/26/10 2/23/10 3/29/10 4/27/10 5/19/10 5/25/10 6/21/10 10/31/02 10/31/02 12/31/02 12/31/02 1DEQ 2Level II 3JSCS PAHs RBCs Aquatic SLVs Table 3-1 Filtered Filtered acenaphthene ug/L -- 520 0.2 0.297 1.03 0.117 0.489 0.0721 0.143 0.261 0.5 0.54 0.1 U 0.1 U acenaphthylene ug/L -- -- 0.2 0.0194 U 0.0313 0.0194 U 0.0196 U 0.0196 U 0.0196 U 0.0194 U 0.1 U 0.1 U 0.1 U 0.1 U anthracene ug/L -- 13 0.2 0.0271 0.0898 0.0194 U 0.0416 0.0196 U 0.0196 U 0.0194 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(a)anthracene ug/L 9.1 0.027 0.018 0.0222 0.0399 0.00971 U 0.0185 0.0146 0.0098 U 0.00971 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(a)pyrene ug/L 0.53 0.014 0.018 0.0178 0.0232 0.00971 U 0.0127 0.0129 0.0098 U 0.00971 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(b)fluoranthene ug/L -- -- 0.018 0.00971 U 0.0108 0.00971 U 0.0098 U 0.0125 0.0098 U 0.00971 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(g,h,i)perylene ug/L -- -- 0.2 0.0194 U 0.0194 U 0.0194 U 0.0196 U 0.0196 U 0.0196 U 0.0194 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(k)fluoranthene ug/L -- -- 0.018 0.0116 0.0133 0.00971 0.0098 U 0.0096 U 0.0098 U 0.00971 U 0.1 U 0.1 U 0.1 U 0.1 U chrysene ug/L -- -- 0.018 0.0248 0.0412 0.0151 0.02 0.028 0.0098 U 0.00971 U 0.1 U 0.1 U 0.1 U 0.1 U dibenzo(a,h)anthracene ug/L 0.21 -- 0.018 0.00971 U 0.00971 U 0.00971 U 0.0098 U 0.0098 U 0.0098 U 0.00971 U 0.2 U 0.2 U 0.2 U 0.2 U fluoranthene ug/L -- 6.2 0.2 0.0466 0.141 0.0342 0.0611 0.0426 0.0196 U 0.0206 0.1 U 0.1 U 0.1 U 0.1 U fluorene ug/L -- 3.9 0.2 0.139 0.551 0.0504 0.19 0.0275 0.0533 0.0958 0.17 0.17 0.1 U 0.1 U indeno(1,2,3-cd)pyrene ug/L -- -- 0.018 0.00971 U 0.0105 0.00971 U 0.0098 U 0.0098 U 0.0098 U 0.00971 U 0.1 U 0.1 U 0.1 U 0.1 U naphthalene ug/L 500 620 0.2 0.627 0.673 0.129 0.687 0.0966 0.51 0.94 0.1 U 0.1 U 0.1 U 0.1 U phenanthrene ug/L -- 6.3 0.2 0.11 0.479 0.0384 0.193 0.0513 0.085 0.128 0.1 U 0.1 U 0.1 U 0.1 U pyrene ug/L -- -- 0.2 0.113 0.358 0.0623 0.122 0.0781 0.0196 U 0.0277 0.22 0.1 U 0.1 U 0.1 U Total PAHs ug/L 1.44 3.49 0.456 1.83 0.436 0.79 1.47 0.89 0.71 0.1 U 0.1 U VOCs benzene ug/L 1,700 130 1.2 0.50 U 0.5 U ethylbenzene ug/L 4,400 7.3 7.3 0.50 U 0.5 U toluene ug/L 210,000 9.8 9.8 0.50 U 0.5 U total xylene ug/L 23,000 -- 200 1.00 U 1 U TPH diesel range ug/L 360 -- -- 250 U 250 U 250 U 250 U motor oil range ug/L 1,100 -- -- 500 U 500 U 500 U 500 U gasoline range ug/L 420 -- -- 80 U 80 U Notes: 1 DEQ risk-based concentrations (RBC) for groundwater in an excavation exposure scenario, last revised June 7, 2012. (DEQ, 2012) -- = no established screening value 2 DEQ Level II Screening Level Values. Table 1, Surface Water, Aquatic. 3 Portland Harbor Joint Source Control Strategy (JSCS) Screening levels taken from Table 3-1 Screening level Values for Stormwater, Revised 7/16/07. (DEQ, 2007) 4 Tanner Creek Sewer Investigation and Evaluation, Former Hoyt Street Railyard (RETEC, 2004) 5 Centennial Mills SCE (Hart Crowser, 2013) 6 Tanner Creek Water Quality Characterization Tech Memo (City of Portland BES, 2011) J = estimated concentration - analyte detected but below instrument calibration. PAHs = polynuclear aromatic hydrocarbons Shaded indicates the dectected analyte that exceeds the screening value. TPH = total petroleum hydrocarbons U = nondetect ug/L = micrograms per Liter VOCs = volatile organic carbons

Page 7 of 9 TABLE 4 Analytical Summary of Stormwater Samples for the 27 inch Storm Sewer, Tanner Creek CSS, and Outfall 11 Portland Terminal Railroad Company Portland, OR Tanner Creek CSO (below 27") Tanner Creek CSO (above 27") Sample Location RASS-24 RASS-14 Constituent Units Sample Date 10/31/02 10/31/02 10/31/02 12/31/02 12/31/02 12/31/02 12/31/02 1DEQ 2Level II 3JSCS PAHs RBCs Aquatic SLVs Table 3-1 Filtered Filtered acenaphthene ug/L -- 520 0.2 0.47 0.50 0.56 0.486 0.5 U 0.609 0.756 acenaphthylene ug/L -- -- 0.2 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U anthracene ug/L -- 13 0.2 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(a)anthracene ug/L 9.1 0.027 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(a)pyrene ug/L 0.53 0.014 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(b)fluoranthene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(g,h,i)perylene ug/L -- -- 0.2 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U benzo(k)fluoranthene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U chrysene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U dibenzo(a,h)anthracene ug/L 0.21 -- 0.018 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U 0.2 U fluoranthene ug/L -- 6.2 0.2 0.1 U 0.1 U 0.1 U 0.162 0.1 U 0.1 U 0.1 U fluorene ug/L -- 3.9 0.2 0.12 0.13 0.18 0.224 0.142 0.358 0.32 indeno(1,2,3-cd)pyrene ug/L -- -- 0.018 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U 0.1 U naphthalene ug/L 500 620 0.2 0.1 U 0.1 U 0.1 U 0.357 1.71 4.25 7.29 phenanthrene ug/L -- 6.3 0.2 0.1 U 0.1 U 0.1 U 0.171 0.1 U 0.568 0.364 pyrene ug/L -- -- 0.2 0.21 0.1 U 0.27 0.313 0.1 U 0.163 0.1 U Total PAHs ug/L 0.80 0.63 1.01 1.713 1.85 VOCs benzene ug/L 1,700 130 1.2 0.50 U 0.50 U 2.32 4.05 ethylbenzene ug/L 4,400 7.3 7.3 0.50 U 0.50 U 104 1.85 toluene ug/L 210,000 9.8 9.8 0.50 U 0.50 U 0.5 U 0.5 U total xylene ug/L 23,000 -- 200 1.00 U 1.00 U 1 U 1 U TPH diesel range ug/L 360 -- -- 250 U 250 U 250 U 316 J 250 U 1050 250 U motor oil range ug/L 1,100 -- -- 500 U 500 U 500 U 500 500 U 500 U 500 U gasoline range ug/L 420 -- -- 80 U 80 U 80 80 U Notes: 1 DEQ risk-based concentrations (RBC) for groundwater in an excavation exposure scenario, last revised June 7, 2012. (DEQ, 2012) -- = no established screening value 2 DEQ Level II Screening Level Values. Table 1, Surface Water, Aquatic. 3 Portland Harbor Joint Source Control Strategy (JSCS) Screening levels taken from Table 3-1 Screening level Values for Stormwater, Revised 7/16/07. (DEQ, 2007) 4 Tanner Creek Sewer Investigation and Evaluation, Former Hoyt Street Railyard (RETEC, 2004) 5 Centennial Mills SCE (Hart Crowser, 2013) 6 Tanner Creek Water Quality Characterization Tech Memo (City of Portland BES, 2011) J = estimated concentration - analyte detected but below instrument calibration. PAHs = polynuclear aromatic hydrocarbons Shaded indicates the dectected analyte that exceeds the screening value. TPH = total petroleum hydrocarbons U = nondetect ug/L = micrograms per Liter VOCs = volatile organic carbons

Page 8 of 9 TABLE 5 Analytical Summary of River Sediment Samples near Outfall 11 Portland Terminal Railroad Company Portland, OR Sample ID 2T1S-09 2WR-PG-130 3SED-1 3TP-2 3TP-4 3TP-5 Date 6/22/00 5/23/05 12/13/99 6/2/06 6/2/06 6/2/06

Parameter Units Depth Interval (cm) 0-10 0-21 0-15 0-30 0-30 0-30 1 Conventional Screening values Total Organic Carbon %/dyr 1.76 2.08 Total Solids %/wet 54.9 46.9 Inorganics lead mg/kg 17 13.8 16.4 33.2 2.86 4.67 4.73 mercury mg/kg 0.07 0.56 0.056 0.92 0.021 J 0.014 J 0.0191 nickel mg/kg 48.6 23.2 24 J 3.45 20.4 17.3 19 copper mg/kg 149 30.1 48.4 J 17.5 14 17.3 antimony mg/kg 64 0.09 0.1 J 0.32 0.021 J 0.0395 J 0.034 J arsenic mg/kg 7 3.3 3.5 1.1 0.835 U 0.687 U 0.776 U cadmium mg/kg 1 0.18 0.222 0.14 0.096 0.0686 0.0907 chromium mg/kg 111 23.6 27 2.28 22.5 17.5 21.9 silver mg/kg 5 0.13 0.261 0.16 0.173 0.121 UJ 0.131 UJ zinc mg/kg 459 93.9 89.5 44.1 75.6 72.7 78.4 tributyltin ug/kg 2.3 0.05 UJ 0.0013 U PAHs naphthalene ug/kg 561 38 320 50 U 16.9 UJ 73.4 15.9 UJ acenaphthylene ug/kg 200 20 U 71 50 U 11 UJ 9.6 U 10.4 UJ acenaphthene ug/kg 200 20 U 160 50 U 14.6 UJ 12.8 U 13.8 UJ fluorene ug/kg 536 20 U 230 50 U 18.2 UJ 8.89 U 9.61 UJ anthracene ug/kg 845 23 270 50 U 10.4 UJ 9.08 U 9.81 UJ phenanthrene ug/kg 1,170 96 1500 50 U 31 J 38 J 20 J fluoranthene ug/kg 2,230 68 620 50 U 41 J 56.5 28.5 UJ pyrene ug/kg 1,520 85 950 50 U 50 J 64.4 28 J benzo(a)anthracene ug/kg 1,050 34 300 50 U 28 J 23 J 17 UJ chrysene ug/kg 1,290 44 350 50 U 24 J 25 J 14.6 UJ benzo(a)pyrene ug/kg 1,450 40 330 50 U 26.8 UJ 23.4 U 25.3 UJ benzo(b)fluoranthene ug/kg -- 36 140 50 U 24.2 UJ 23 J 22.8 UJ benzo(k)fluoranthene ug/kg 13,000 30 170 50 U 10.3 UJ 8.99 U 9.71 UJ benzo(g,h,i)perylene ug/kg 300 36 180 50 U 17 UJ 14.8 U 16 UJ indeno(1,2,3-cd)pyrene ug/kg 100 37 180 50 17.3 UJ 15.1 U 16.3 UJ dibenzo(a,h)anthracene ug/kg 1,300 20 U 41 50 U 15.1 UJ 13.2 U 14.2 UJ Total PAHs ug/kg 567 6250 PCBs Aroclors Aroclor 1016 ug/kg 530 10 U 2.8 U 10 U 1.01 U 0.881 U 0.952 U Aroclor 1242 ug/kg -- 10 U 2.8 U 10 U 1.01 U 0.881 U 0.952 U Aroclor 1248 ug/kg 1500 10 U 2.5 U 10 U 1.01 U 0.881 U 0.952 U Aroclor 1254 ug/kg 300 10 U 13 J 10 U 1.01 U 0.881 U 0.952 U Aroclor 1221 ug/kg -- 20 U 2.5 U 20 U 1.01 U 0.881 U 0.952 U Aroclor 1232 ug/kg -- 20 U 2.5 U 10 U 1.01 U 0.881 U 0.952 U Aroclor 1260 ug/kg 200 19 20 10 U 1.01 U 0.881 U 0.952 U TPH diesel range mg/kg 150 J motor oil range mg/kg 900 J gasoline range mg/kg 2.2 U Notes: -- = no established RBC 1 Portland Harbor Joint Source Control Strategy (JSCS) Screening levels taken from Table 3-1 Screening level Values for Sediment, Revised 7/16/07. (DEQ, 2007) 2 Data found in Portland Harbor RI/FS Sediment Data River Mile 11.4 west bank (LWG, 2009). 3 Centennial Mills Final Upland Source Control Evaluation (Hart Crowser, 2013) J = estimated concentration - analyte detected but below instrument calibration. mg/kg = milligrams per kilogram PAHs = polynuclear aromatic hydrocarbons Shaded indicates the dectected analyte exceeds the screening value. U = nondetect ug/kg = micrograms per kilogram VOCs = volatile organic carbons

Table 6 Air Sampling Data Summary Station Place

Sample location Outdoor Roof Outdoor Intersection of NW 9th & NW Lovejoy Sample date 12/23/2004 3/20/2006 9/8/2006 7/26/2007 11/19/2008 7/17/2009 7/15/2010 12/23/2004 8/18/2005 3/20/2006 9/8/2006 7/26/2007 11/19/2008 1Screening 1020 NW Lovejoy 1044 NW Lovejoy 1020 NW Lovejoy VOCs Units values Chloromethane ug/m3 94 0.73 0.86 0.62 0.68 0.95 1.2 0.28 0.67 0.45 0.89 0.77 0.65 0.82 Vinyl chloride ug/m3 0.2 0.033 U 0.037 U 0.39 U 0.04 U 0.032 U 0.035 U 0.046 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U chloroethane ug/m3 10000 0.033 U 0.05 0.053 0.04 U 0.032 U 0.035 U 0.03 U 0.033 U 0.051 0.037 U 0.18 0.036 U 0.037 U 1,1-Dichloroethene ug/m3 210 0.033 U 0.037 U 0.039 U 0.04 U 0.032 U 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U Methylene chloride ug/m3 -- 0.31 0.3 0.31 0.17 1.7 0.31 0.18 0.26 0.38 0.26 0.29 0.18 0.39 Trichlorotrifluoroethane ug/m3 -- 0.49 0.6 0.34 0.32 0.55 0.63 0.54 0.44 0.53 0.62 0.35 0.32 0.55 1,2-Dichloroethene trans- ug/m3 63 0.033 U 0.037 U 0.039 U 0.04 U 2.5 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U 1,1-Dichloroethane ug/m3 4.1 0.033 U 0.037 U 0.039 U 0.04 U 0.032 U 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U 1,2-Dichloroethene cis- ug/m3 >Pv 0.033 U 0.037 U 0.039 U 0.1 0.032 U 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U chloroform ug/m3 0.29 0.13 U 0.15 U 0.16 U 0.15 U 0.19 0.14 U 0.12 U 0.13 U 0.16 U 0.15 0.15 U 0.14 U 0.15 U 1,2-Dichloroethane ug/m3 -- 0.042 0.049 0.039 U 0.04 U 1.1 0.07 0.1 0.033 U 0.039 U 0.046 0.038 U 0.036 U 0.058 1,1,1-Trichloroethane ug/m3 5200 0.11 0.097 0.042 0.04 0.06 0.062 0.045 0.1 0.11 0.099 0.039 0.038 0.059 Benzene ug/m3 0.85 1.1 0.96 0.46 0.37 2.2 0.67 0.22 1.1 0.9 0.98 1 0.58 1.3 Carbon Tetrachloride ug/m3 1.1 0.57 0.5 0.16 U 0.23 0.45 0.53 0.46 0.52 0.37 0.51 0.15 U 0.24 0.43 1,2-Dichloropropane ug/m3 -- 0.033 U 0.037 U 0.039 U 0.04 U 1.5 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.071 Trichloroethene ug/m3 1 0.12 0.058 0.029 0.18 0.67 0.035 U 0.03 U 0.045 0.048 0.058 0.027 0.036 U 0.099 1,3-Dichloropropene cis- ug/m3 -- 0.033 U 0.037 U 0.039 U 0.04 U 0.057 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.051 1,1,2-Trichloroethane ug/m3 0.21 0.033 U 0.037 U 0.039 U -- 0.032 U 0.035 U 0.12 U 0.033 U 0.039 U 0.037 U 0.038 U -- 0.037 U Toluene ug/m3 5200 5.4 1.6 1.6 1.4 87 4.4 0.94 3.7 3.6 1.5 2.5 1.4 5.2 1,2-Dibromoethane ug/m3 -- 0.033 U 0.037 U 0.039 U 0.04 U 0.033 U 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U Tetrachloroethene ug/m3 26 0.21 0.11 0.054 0.08 1.4 0.27 0.043 0.16 0.11 0.11 0.051 0.043 0.29 Chlorobenzene ug/m3 52 0.035 0.037 U 0.039 U 0.04 U 0.13 0.035 U 0.12 U 0.033 U 0.042 0.037 U 0.038 U 0.036 U 0.15 U Ethylbenzene ug/m3 2.7 0.7 0.32 0.47 0.21 18 1.1 0.13 0.6 0.49 0.28 0.5 0.32 0.9 1,1,2,2-Tetrachloroethane ug/m3 -- 0.033 U 0.037 U 0.039 U 0.04 U 0.032 U 0.035 U 0.03 U 0.033 U 0.039 U 0.037 U 0.038 U 0.036 U 0.037 U 1,4-Dichlorobenzene ug/m3 0.6 0.076 0.57 0.052 0.05 0.25 0.058 0.03 U 0.3 0.06 0.037 U 0.038 U 0.036 U 0.063

Notes: -- = no established RBC 1 DEQ risk-based concentration (RBC) for air inhalation for the Urban residential scenario, last revised June 7, 2012. (DEQ, 2012) Data collected from Station Place Redevelopment Site (The Tower and Ziba Headquarters Office Building) 1020 & 1044 NW 9th Ave (AMEC, 2009 a,, 2009b, and 2010). ft bgs = feet below ground surface VOCs = volatile organic compounds ug/m3 = micrograms per cubic meter Shaded indicates the detected analyte exceeds the screening value. U = analyte not detected at or above the indicated method reporting limit >Pv=The air concentration reported for the RBC exceeds the vapor pressure of the pure chemical. It can be assumed that this constituent cannot create an unacceptable risk by this pathway.

Page 1 of 2 Table 6 Air Sampling Data Summary Station Place

Sample location Vapor System Sample date 8/19/2005 3/20/2006 9/8/2006 7/26/2007 11/19/2008 7/17/2009 7/15/2010 1Screening 1020 NW Lovejoy 1044 NW Lovejoy VOCs Units values Chloromethane ug/m3 94 0.98 0.81 0.4 0.33 0.87 1.2 0.37 Vinyl chloride ug/m3 0.2 0.18 0.035 U 0.14 0.033 U 0.033 U 0.035 U 0.033 U chloroethane ug/m3 10000 0.4 0.035 U 0.13 0.1 0.16 0.035 U 0.033 U 1,1-Dichloroethene ug/m3 210 0.092 0.035 U 0.035 U 0.033 U 0.033 U 0.035 U 0.033 U Methylene chloride ug/m3 -- 0.28 U 0.25 1.1 0.48 0.33 0.34 0.18 Trichlorotrifluoroethane ug/m3 -- 0.52 0.61 0.33 0.3 0.55 0.62 0.54 1,2-Dichloroethene trans- ug/m3 63 0.071 U 0.035 U 0.035 U 0.033 U 0.033 U 0.035 U 0.033 U 1,1-Dichloroethane ug/m3 4.1 0.071 U 0.035 U 0.042 0.033 U 0.033 U 0.035 U 0.033 U 1,2-Dichloroethene cis- ug/m3 >Pv 0.071 U 0.035 U 0.035 U 0.22 0.033 U 0.035 U 0.033 U chloroform ug/m3 0.29 1.1 0.14 U 0.68 0.83 0.13 U 0.15 0.13 U 1,2-Dichloroethane ug/m3 -- 0.071 U 0.044 0.035 U 0.33 U 0.06 0.066 0.055 1,1,1-Trichloroethane ug/m3 5200 0.11 0.095 0.045 0.047 0.05 0.057 0.043 Benzene ug/m3 0.85 1.2 0.85 0.45 0.39 0.84 0.46 0.21 Carbon Tetrachloride ug/m3 1.1 1.4 0.51 0.14 0.97 0.42 0.54 0.47 1,2-Dichloropropane ug/m3 -- 0.071 U 0.035 U 0.035 U 0.033 U 0.049 0.035 U 0.033 U Trichloroethene ug/m3 1 0.071 U 0.056 0.027 0.17 0.15 0.035 U 0.033 U 1,3-Dichloropropene cis- ug/m3 -- 0.071 U 0.035 U 0.035 U 0.033 U 0.17 0.035 U 0.033 U 1,1,2-Trichloroethane ug/m3 0.21 0.071 U 0.035 U 0.035 U 0.033 U 0.033 U 0.035 U 0.13 U Toluene ug/m3 5200 3.3 1 0.95 1.3 2.7 3.4 0.89 1,2-Dibromoethane ug/m3 -- 0.071 U 0.035 U 0.035 U 0.033 U 0.033 U 0.035 U 0.033 U Tetrachloroethene ug/m3 26 0.33 0.16 0.75 0.72 0.23 0.087 0.041 Chlorobenzene ug/m3 52 0.071 U 0.035 U 0.035 U 0.033 U 0.13 U 0.035 U 0.13 U Ethylbenzene ug/m3 2.7 0.55 0.21 0.23 0.32 0.45 0.65 0.18 1,1,2,2-Tetrachloroethane ug/m3 -- 0.071 U 0.035 U 0.035 U 0.033 U 0.033 U 0.035 U 0.033 U 1,4-Dichlorobenzene ug/m3 0.6 0.071 U 0.035 U 0.035 U 0.033 U 0.092 0.035 U 0.033 U

Page 2 of 2

Figures

Outfall 11

QUIMBY CDF placement

NAITO

ATCS severed by Tanner Creek CSS in 1917

11TH

OVERTON

NORTHRUP

9TH CDF placement

MARSHALL

STATION

CDF placement

LOVEJOY

NW 9th Avenue and NW Lovejoy Street Intersection

10TH

Aerial Photo Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, LEGEND Getmapping, Aerogrid, IGN, IGP, and the GIS User Community Abandoned Tanner Creek Sewer 27 inch Storm Sewer FIGURE 1 Tanner Creek CSS Area of Interest Including Area of Interest ¯ Sewer Lines near NW 9th Ave 040 80 160 240 and NW Lovejoy Street CDF placed in ATCS Feet Portland Terminal Railroad Company Portland, OR \\ROSA\PROJ\PTRR\418023\GIS\MAPFILES\FIGURE1.MXD GGEE 5/1/2014 8:09:05 AM

Notes Low Ground

Fill

Gasholder on Concrete Foundation

Crude Oil Tank 7500 gallons 2 feet underground

Purifier room

2 Retorts

Planned yard

Line of bank N

Figure 3 1901 Sanborn Map of Pintsch MGP area Portland Terminal Railroad Company Portland, Oregon

Map from Environmental Data Resources, Inc. Used with permission. Notes Notes

Gas made from Oil tan ks 2 feet crude oil underground

Gas tank High pressure tanks 3 Retorts Compressing room Tar well Purifying room

Oil tanks underground

Figure 4 1908 Sanborn Map of Pintsch MGP area Portland Terminal Railroad Company Portland, Oregon

Map from Environmental Data Resources, Inc. Used with permission. Notes

Asphalt plant with asphalt and fuel oil

Pintsch MGP with crude oil

Columbia Steel Foundry with open coke bin and unddderground oil storage N

Figure 5 Larger‐scale view, 1908 Sanborn Map of Pinttsch MGP area Portland Terminal Railroad Company Portland, Oregon Map from Environmental Data Resources, Inc. Used with permission.

ATCS plugged in 1917 Outfall 11

CDF placement QUIMBY

NAITO

ATCS severed by Tanner Creek CSS in 1917

11TH

OVERTON

NORTHRUP

9TH CDF placement

MARSHALL

STATION

CDF placement

LOVEJOY

NW 9th Avenue and NW Lovejoy Street 12TH Intersection

10TH

Aerial Photo Source: Esri, i-cubed, USDA, USGS, AEX, GeoEye, LEGEND Getmapping, Aerogrid, IGN, IGP, and the GIS User Community CDF placed in ATCS Tanner Creek CSS Approximate Area Shallow Soil Exceeds Excavation 27 inch Storm Sewer Worker RBCs Abandoned Tanner Creek Sewer Approximate Area Shallow Groundwater Exceeds FIGURE 10 Excavation Worker RBCs Approximate Areas Exceeding Approximate Area of Recommended Environmental Excavation Worker RBCs Monitoring for Excavation Work ¯ Portland Terminal Railroad Company 040 80 160 240 Feet Portland, OR \\ROSA\PROJ\PTRR\418023\GIS\MAPFILES\FIGURE11.MXD GGEE 5/1/2014 8:16:06 AM

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