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Human Health Risk Assessment and Level 1 and Level II Ecological Risk Assessments - Library - July 11, 2008
A 1 iI 'I i GEoErvciH¢exS VIII cif t III ' glulll 1 Earth Scienc. Technology ,ter AN 40 rir HUMAN HEALTH RISK ASSESSMENT AND LEVEL I AND LEVEL II ECOLOGICAL RISK ASSESSMENTS TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON JULY 11, 2008 FOR CITY OF TIGARD GEOENGINEERS� Fite No 4025-003-02 irr Human Health Risk Assessment and Level I and Level II Ecological Risk Assessments Tigard Library 13500 SW Hall Boulevard Tigard, Oregon July 11, 2008 Prepared for: City of Tigard 13125 SW Hall Boulevard Tigard, Oregon 97223 Attention: Dennis Koellermeier wtt Prepared by: GeoEngineers, Inc. 15055 SW Sequoia Parkway, Suite 140 Portl nd, Oregon 97224 tS T� eil Morton Senior Environmental Scientist gRis i Chris W. Breemer, R.G. Q3P A Senior ct a r aO V wr ohn H. Biggane Principal NFM:CWl3 JHB:gaw Port: P:\4\4025003\02\Finals\402500302HHRA-ERA.doe Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided. and any attachments are only a copy of the original document. The original document is stored by GeoE nvineers, Inc and will serve as the official document of record. Copyright©2008 by GeoEngineers, Inc. All rights reserved- File No 4025-003-02 IrM TABLE OF CONTENTS Page No. W 1.0 INTRODUCTION.................................................................................................................................... 1 1.1 REPORT OUTLINE................................................. , 2.0 SITE DESCRIPTION..............................................................................................................................1 2.1 PHYSICAL SETTING...................................................................................................................1 f 2.2 SITE SETTING.............................................................................................................................2 2.3 RECENT CONSTRUCTION............................................. ......... ...............................................2 2.3.1 Soil Removed During Recent Construction.....................................................................2 2.4 GEOLOGY AND HYDROGEOLOGY...........................................................................................3 3.0 SITE INVESTIGATION ACTIVITIES......................................................................................................3 3.1 HAHN ASSOCIATES 2002 PHASE II ENVIRONMENTAL SITE ASSESSMENT.......................3 iw 3.2 APEX 2002 —2003 ASSESSMENTS AND 2004 SOIL REMOVAL.............................................3 3.3 HAHN ASSOCIATES 2005 ASSESSMENT AND REMEDIATION..............................................4 3.4 GEOENGINEERS 2007 ASSESSMENT .....................................................................................4 3.4.1 April 2007 Assessment.....................................................................................................4 3.4.2 June 2007 Assessment....................................................................................................4 3.5 GEOENGINEERS 2008 SOIL AND SURFACE WATER INVESTIGATION................................5 as 3.5.1 February-March 2008 Surface Water Sampling........ .....................................................5 3.5.2 May 2008 Soil/Sediment Sampling..................................................................................5 4.0 CONCEPTUAL SITE MODEL................................................................................................................7 rrf 4.1 POTENTIAL CONTAMINANT SOURCES...................................................................................7 4.2 NATURE AND EXTENT OF CONTAMINATION .........................................................................7 4.2.1 Soil/Sediment...................................................................................................................7Ir 4.2.2 Groundwater....................................................................................................................8 4.3 CONTAMINANTS OF INTEREST................................................................................................8 4.4 BENEFICIAL LAND AND WATER USE DETERMINATION........................................................8 4.4.1 Locality of the Facility ......................................................................................................8 4.4.2 Current and Reasonably Likely Future Land Use ...........................................................9 4.4.3 Current and Reasonably Likely Beneficial Use of Water............................................... 10 4.5 POTENTIAL RECEPTOR-EXPOSURE PATHWAYS................................................................ 10 5.0 RISK-BASED SCREENING.................................................................................................................11 5.1 DATA EVALUATION..................................................................................................................11 10 5.1.1 Human Health Data Sets...............................................................................................11 5.1.2 Ecological Data Sets......................................................................................................11 5.1.3 Calculation of Exposure Point Concentrations and Environmental Concentrations ...... 12 5.2 HHRA RESULTS........................................................................................................................ 12 5.2.1 Exposure Assumptions and RBCs ................................................................................ 13 5.2.2 Risk Characterization..................................................................................................... 13 5.2.3 Summary ........................................................................................................................14 5.3 ERA RESULTS ..........................................................................................................................14 5.3.1 Terrestrial Evaluation.....................................................................................................15 5.3.2 Aquatic Evaluation.........................................................................................................15 File No. 4025-003-02 Page i GEOENGINEER July 11,2008 TABLE OF CONTENTS (CONTINUED) Page No. 6.0 CONCLUSIONS...................................................................................................................................15 7.0 REFERENCES..................................................................................................................................... 15 �r List of Tables Table 1. Soil Analytical Results Table 2. Pond Discharge Analytical Results Table 3. Summary of Soil Analytical Data by Depth Table 4. Human Health Risk-Based Screening, Arsenic in Soil wr List of Figures ■w Figure 1. Vicinity Map Figure 2. Site Layout Figure 3. Current and Historic Soil Sample Locations Figure 4. Supplemental Investigation Sample Locations with Arsenic Data Figure 5. Conceptual Site Model Figure 6. Box Plot of Arsenic Concentrations in Soil by Depth Figure 7. Areas Exceeding Screening Criteria APPENDICES rrt APPENDIX A— LABORATORY ANALYTICAL DATA...................................................................A-1 ... A-8 APPENDIX B— LEVEL I AND II ECOLOGICAL RISK ASSESSMENTS....................................... B-1 ... B-8 Appendix B Tables Table B-1. Federal and State of Oregon Special Status Species Table B-2. List of Plants and Animals Observed During the Level I ERA Scoping Site Visit rrr Table B-3. Site-Specific Habitat, Media/Pathways, and Candidate Receptors Table B-4. Contaminants of Potential Ecological Concern, Arsenic in Soil Table B-5. Contaminants of Potential Ecological Concern, Arsenic in Soil/Sediment at Stream/Wetland Restoration Area Appendix B Figures Figures B-1 through B-8. Site Photographs APPENDIX C—COMPILATION OF CHEMICAL ANALYTICAL DATA +rr APPENDIX D— REPORT LIMITATIONS AND GUIDELINES FOR USE......................................D-1 ... D-3 w File No. 402500302 Page[1 GEOENGINEERSL July 11, 2008 irw HUMAN HEALTH RISK ASSESSMENT AND LEVEL I AND LEVEL II ECOLOGICAL RISK ASSESSMENTS TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON FOR CITY OF TIGARD 1.0 INTRODUCTION This report presents a Human Health Risk Assessment (HHRA) and Level I and Level II ecological risk assessments (ERAS) for the Tigard Library facility located at 13500 SW Hall Boulevard in Tigard, Oregon (site). Soil at the site is contaminated with arsenic, most of which apparently migrated to the site by overland flow from orchards that were historically present west of the site. The purpose of the HHRA and the ERAs is to identify cleanup levels that are protective of hurnan and ecological health under current and reasonably likely future conditions. aft The location of the site relative to surrounding physical features is shown in Figure 1. The site layout is shown on Figure 2. This report was prepared in general accordance with Oregon Administrative Rules (OAR) 340-122-0205 through 340-122-0360. GeoEngineers prepared this report on behalf of the City of Tigard (City) in accordance with our proposal dated January 7, 2007 and City Purchase Order number 7-1165. M" 1.1 REPORT OUTLINE This document includes: • Site Description (Section 2.0). Irw • Previous Site Investigation Activities (Section 3.0). • Conceptual Site Model (Section 4.0). ft • Risk-Based Screening(Section 5.0). • References (Section 6.0). • Laboratory Analytical Data(Appendix A). • Level I and II Ecological Risk Assessment (Appendix B). • Summary of Chemical Data in Digital Format (Appendix Q. 2.0 SITE DESCRIPTION err The following sections describe the site's physical, geologic and hydrogeologic setting. 2.1 PHYSICAL SETTING The site is located at the east of the intersection of SW Hall Boulevard and SW Wall Street in Washington County in Tigard, Oregon. Fanno Creek borders the north and east sides of the site. The approximate w Page I GMENGINEERs File No. 4025-003-02 July 11,2008 AN as 14.7-acre site is located in Township 2 South, Range 1 West, in the northeast quarter of the southeast quarter of Section 2, of the Willamette Meridian. The site is defined as the property occupied by the library facility (Washington County tax lots as 2S102DA00600, 2S102DD00100, and 2S102DD00200), public rights-of-way (ROW) adjacent to the south (Wall Street) and west (Hall Boulevard) sides of the library property, and stream/wetland areas at the south and southeast of these areas. The site does not include Fanno Creek or areas north or east of '" Fanno Creek. 2.2 SITE SETTING The site is currently occupied by a library and associated parking and vegetated areas. A pedestrian trail traverses the east and north sides of the site, The elevation of most of the site is approximately 150 feet above mean sea level (MSL). The site is relatively flat, with the exception of a low area occupied by Pinebrook Stream that traverses the south side of the site in a west-east direction. A gentle swale, oriented in a southwest-northeast direction, runs through the middle of the site. Much of the southwest- northeast trending swale was filled during construction of the library, and that the swale no longer channels storm water at the site. Pinebrook Stream flows across the south side of the site, after entering the site through a culvert underneath Hall Boulevard. Pinebrook Stream discharges to Fanno Creek near the southeast corner of the site. A storm water pond (the "pond") is located at the SE corner of the site, adjacent to and north of Pinebrook Stream. The pond receives stormwater runoff from parking areas at the site. The stormwater enters the north side of the pond through a constructed channel. During high water events, the pond and Pinebrook Stream may be connected. Site surface water features are shown on Figure 2. Fanno Creek is a perennial stream with heavily vegetated banks that are approximately 5 feet high. Fanno Creek discharges to the Tualatin River approximately 2 miles south of the site. The location of Fanno Creek is shown in Figure 1. The site is bordered by residences to the west and south and vacant land to the north and east. Southwest Hall Boulevard borders the west side of the site. 2.3 RECENT CONSTRUCTION rn The City completed a number of construction activities at the site during the summer and fall of 2007, including: 1) extending Wall Street across approximately half of the south side of the site; 2) constructing a driveway to the residential properties south of the site; 3) adding additional parking areas between the Wall Street extension and the older parking areas and 4) restoring Pinebrook Stream and associated wetland areas at the south and southeast portions of the site. The construction activities were summarized in GeoEngineers' Revised Construction Summary Report, dated March 11, 2008. rr 2.3.1 Soil Removed During Recent Construction The 2007 construction activities included cutting and filling some areas of the site. The cut and fill +r+ activities are described in detail in the construction summary report. The construction activities included two activities that are pertinent for understanding the risks posed by arsenic in soil and sediment at the site: on File No.4025-003-02 Page 2 GWENGINEERS� July 11,2008 rr Wlw • Approximately 250 cubic yards of arsenic-contaminated soil were inadvertently moved from the west end of the library driveway (near the intersection of Hall Boulevard and Wall Street) to the east end of the driveway. The contaminated soil was placed in an area referred to as the "Fill Area" (shown on Figure 2). GeoEngineers collected two soil samples from the Fill Area in May 2008. The sample data confirmed that the soil in the Fill Area contains arsenic at concentrations exceeding the DEQ default background concentration (see Section 3.4). • As much as 4 to 5 feet of soil were removed in the stream/wetland restoration area and transported off-site for disposal at a the Hillsboro Landfill, a U.S. Resource Conservation and Recovery Act (RCRA) Subtitle D landfill facility. Analytical data for samples that represent the removed soil were excluded from the human and ecological risk evaluation (Section 5.0). 2.4 GEOLOGY AND HYDROGEOLOGY The surface of the site is generally covered with trees, shrubs, grasses, and in some areas, asphalt and concrete. Organic sandy silt with some clay is present in the upper 2 to 5 feet of soil (Shannon and Wilson, 2003). Silt with varying amounts of clay and sand, but fewer organics is present below the upper organic layer and extends to at least 10 feet bgs, the maximum depth explored at the site. a„ Groundwater has been encountered at depths ranging between 2 and 9 feet below ground surface (bgs). Shallow ground water presumably flows toward Fanno Creek. r 3.0 SITE INVESTIGATION ACTIVITIES Several phases of soil assessment and remediation have been completed at the site between 2002 and the present. Past investigation activities are described in the following sections. Soil sample locations from previous and current site investigation activities are shown on Figure 3. Corresponding soil chemical analytical data are presented in Table 1. ` 3.1 HAHN ASSOCIATES 2002 PHASE II ENVIRONMENTAL SITE ASSESSMENT I� Hahn Associates, Inc. (HAI) conducted a Phase II Environmental Site Assessment (ESA) at the site in 2002 to evaluate potential impacts to the site from agricultural chemicals. Hahn submitted soil samples collected at the site for laboratory analysis of arsenic, copper, lead, and mercury by U.S. Environmental , Protection Agency (EPA) 6000/7000 Series methods; organochlorine pesticides by EPA Method 8081 A, and chlorinated herbicides by EPA Method 8151. Pesticides and herbicides were not detected. Only arsenic was detected at concentrations exceeding natural background concentrations. 3.2 APEX 2002—2003 ASSESSMENTS AND 2004 SOIL REMOVAL Apex Environmental Consulting Services, Inc. (Apex) completed two phases of soil assessment in 2002 and 2003 and managed the removal of approximately 3,682 tons of contaminated soil from the site in 2004. Apex submitted approximately 38 soil samples, collected between the ground surface and approximately 3.3 feet bgs, for analysis of arsenic. The assessment and remediation conducted by Apex was primarily completed under the footprint of the library, the pre-2007 parking area, and the driveway. r File No. 4025-003-02 Page 3 GWENGINEERS� July 11, 2008 .rr .r 3.3 HAHN ASSOCIATES 2005 ASSESSMENT AND REMEDIATION HAI conducted additional assessment in 2005. HAI submitted approximately 55 soil samples, collected between the ground surface and approximately 6 feet bgs, for analysis of arsenic. HAI also managed the ' removal of 155 tons of contaminated soil from areas in the footprint of the pedestrian path that traverses the east side of the site. HAI summarized the results of their investigation and remediation, as well as previously completed work in their October 6, 2006, Draft Supplemental Site Investigation Report. HAI's assessment was predominantly conducted in undeveloped areas to the north, east, and south of the library and the pre-2007 parking area. 3.4 GEOENGINEERS 2007 ASSESSMENT GeoEngineers collected soil samples during April and June 2007 from the south portion of the site in rr areas where the Pinebrook Stream channel was scheduled for restoration. The sampling activities are described below and the sample locations are shown on Figure 3. Sample data are summarized in Table 1. GeoEngineers reported the April and June 2007 sampling activities in a memorandum dated July 12, 2007. 3.4.1 April 2007 Assessment a. GeoEngineers collected soil samples from eight locations near the south side of the site during April 2007. GeoEngineers also collected a three-point composite sample for waste profiling purposes. Soil .�r samples were collected from surface (0-1 foot) and subsurface (2-3 feet) intervals at the eight locations (HA-I through HA-8). The composite sample was collected from three locations (HA-9A, HA-913, and HA-9C) in the interval between I and 2 feet(bgs). The composite sample was collected in the vicinity of the pond at the southwest portion of the site, in the area where the highest concentrations of arsenic were previously detected. Arsenic was detected in eight soil samples collected from five borings, at concentrations between 7.22 and 20.4 milligrams per kilogram (mg/kg). The highest concentrations of arsenic were detected in soil collected from boring HA-1, at the southwest side of the site. Arsenic was not detected in samples collected at the far southeast portion of the site (HA-7 and HA-8). Leachable arsenic was not detected in + the composite sample. 3.4.2 June 2007 Assessment GeoEngineers collected subsurface soil samples from eight test pits (SP-I through SP-8) in the planned stream/wetland restoration area on June 21, 2007. The soil samples were collected from target surface for the restored stream/wetland and 2 feet below the target surface. The purpose of the June 2007 sampling event was to evaluate whether the target surface of the stream/wetland contained arsenic at concentrations that would pose a potentially unacceptable risk to ecological receptors. GeoEngineers also collected one soil sample (SP-9) on June 29, 2007 from the finished surface of the stream/wetland area after the stream restoration excavation activities were complete. The purpose of collecting sample SP-9 was to further evaluate soil quality at the target surface of the restored stream channel. I WA File No. 4025-003-02 Page 4 GWENGINEERS� July ll, 2008 yrr Rirw Arsenic was detected in six soil samples collected from eight test pits at concentrations ranging between 7.96 and 21.1 mg/kg. The highest concentrations of arsenic were detected in soil collected from test pit SP-1, at the west side of the site, near the April 2007 hand auger sample HA-1. Arsenic was detected in sample SP-9 at a concentration of 12.2 mg/kg. 3.5 GEOENGINEERS 2008 SOIL AND SURFACE WATER INVESTIGATION GeoEngineers further evaluated soil sediment and surface water quality in areas affected by the 2007 ► construction activities and in the pond between February and May 2008. The 2008 assessment activities were completed in response to requests from DEQ (2007) for additional information about the magnitude and extent of contamination at the site, and in particular, to evaluate whether the site is contributing rr arsenic at unacceptable concentrations to Fanno Creek via discharge of surface water from the pond and from Pinebrook Stream. Figure 4 shows the locations of samples collected in May 2008 and the corresponding arsenic concentrations. Sample data are presented in Table 1. The laboratory reports are , included in Appendix A. 3.5.1 February-March 2008 Surface Water Sampling Irr GeoEngineers collected surface water samples from the outfall of the pond on February 2, 2008 ("Pond Discharge-I") and March 14, 2008 ("Pond Discharge-2"). GeoEngineers collected the samples during ob ongoing storm events during which at least one-half inch of precipitation occurred within the 24 hours preceding collection of the sample. The samples were submitted to Apex Laboratory in Tigard, Oregon for analysis of turbidity by Standard Method (SM) 213013, total suspended solids (TSS) by Method 160.2, and total arsenic by EPA Method 6020. The turbidity of the surface water samples ranged between 15 and 52 nephelometric turbidity units (NTU) and the TSS ranged between 8 and 73 milligrams per liter (mg/1). The total concentration of arsenic in the samples ranged between 1.12 and 1.21 micrograms per liter(µg/1). Stormwater sample data are summarized in Table 2. err A comparison of the detected concentrations of total arsenic to turbidity and TSS indicates that the total concentration of arsenic in surface water samples is relatively unaffected by the suspended load of the samples. For example, the turbidity of the sample collected on March 14, 2008 was approximately 3.5 , times higher than the turbidity measured in the February 2 sample and the TSS of the March 14, 2008 sample was approximately 9 times higher than the TSS in the February 2 sample. Despite the significant increases in turbidity and TSS, the detected concentration of arsenic only increased by approximately 10 , percent between the February and March 2008 samples. 3.5.2 May 2008 Soil/Sediment Sampling GeoEngineers collected 21 soil/sediment samples and two 3-point composite soil samples in May 2008. The sample locations are shown on Figures 3 and 4. The objective of the soil/sediment sampling effort was to obtain additional data necessary to evaluate human and ecological risk at the site and to define the locality of facility (LOF). The following table summarizes the specific purposes of the soil/sediment samples collected in May 2008. File No. 4025-003-02 Page 5 GWENGINEERS� July 11,2008 ar .�r Purpose Samples rr Evaluate the quality of upland soil in recently exposed areas. HA-10(0-1), HA-11(0-1), HA-12(0-1), HA-13(0-1), and HA-14(0-1) Evaluate the quality of soil that was placed in the upland Fill Area. HA-15((0-1)and HA-16(0-1) Evaluate the quality of soil potentially eroding from the pond bank into Fanno HA-20(0-0.5) Creek Evaluate the quality of sediment in submerged areas of the retention pond HA-19(0-0.5), HA-21(0-0.5), and HA- 22(0-0.5) Evaluate soil quality in stream/wetland areas disturbed during the 2007 HA-17(0-1), HA-18(0-1), HA-25(0-1), construction activities. HA-26(0-0.5), COMP-1, and COMP-2 Evaluate sediment quality in Pinebrook Stream. HA-23(0-1), HA-24(0-0.5), HA-27(0- 0.5), HA-28(0-0.5), HA-29(0-0.5), and HA-30(0-0.5 sr The May 2008 soil/sediment samples were collected using a stainless steel hand auger at depths ranging between the ground surface and 2.5 feet bgs. The soil/sediment samples were submitted to Apex .rr Laboratory for analysis of arsenic by EPA Method 6020. The following paragraphs summarize the data obtained during the May 2008 assessment. Table 1 summarizes the chemical analytical data obtained during the May 2008 soil/sediment assessment. �r 3.5.2.1 Samples From Upland Areas Exposed During Construction Activities Soil samples collected from upland areas exposed during the 2007 construction activities exhibited arsenic concentrations ranging between 3.8 and 5.4 mg/kg. 3.5.2.2 Samples From the Upland Fill Area Soil samples collected from the upland Fill Area contain concentrations of arsenic ranging between 9.9 and 13 mg/kg. The chemical analytical data confirm that the soil placed in the Fill Area contains concentrations of arsenic exceeding background concentrations. •� 3.5.2.3 Soil Eroding Into Fanno Creek From the Pond Outfall GeoEngineers collected a soil sample [HA-20(0-0.5)] from a large piece of soil that calved from the pond outfall into the Fanno Creek channel. Sample HA-20 contained 16 mg/kg. 3.5.2.4 Pond Sediment GeoEngineers collected three sediment samples [HA-19(0-0.5), HA-2](0-0.5), and HA-22(0-0.5)] from the pond. The sediment samples contained arsenic at concentrations ranging between 12 and 110 mg/kg. The chemical analytical data confirm that the sediment in the retention pond contains concentrations of arsenic exceeding background concentrations. 3.5.2.5 Soil Quality in Disturbed Areas GeoEngineers collected four soil samples [HA-17(0-1), HA-18(0-1), HA-25(0-1), HA-26(0-0.5), COMP- 1, and COMP-2] from upland areas that were disturbed during the 2007 construction activities. The samples contained concentrations of arsenic ranging between non-detect and 32 mg/kg. w File No. 4025-003-02 Page 6 GWENGINEERS� July 11,2008 rr 3.5.2.6 Sediment Quality in Pinebrook Stream GeoEngineers collected six sediment samples [HA-23(0-1), HA-24(0-0.5), HA-27(0-0.5), HA-28(0-0.5), HA-29(0-0.5), HA-30(0-0.5)] from the Pinebrook Stream channel. The Pinebrook Stream channel samples contained concentrations of arsenic ranging between non-detect and 12 mg/kg. Ift 4.0 CONCEPTUAL SITE MODEL A conceptual site model (CSM) defines the potentially complete exposure pathways by which receptors I1► may be exposed to site contaminants under current or anticipated future conditions. A complete pathway from the contaminant source to a human or ecological receptor is necessary in order for contaminant exposure to occur. A discussion of potential contaminant sources (Section 4.1) and the nature and extent aw of contamination (Section 4.2) are presented in the following sections. A determination of current and reasonably likely future land and beneficial water use at the site and surrounding properties is presented in Section 4.3 and receptor-exposure pathway analysis is presented in Section 4.4. Findings from the go beneficial land and water use determinations have been incorporated into the site-specific CSM that is presented graphically in Figure 5. sk 4.1 POTENTIAL CONTAMINANT SOURCES HAI (2006) reported that transport of arsenic-contaminated soil from up-gradient off-site orchard properties with deposition in historic low-lying drainages and swales at the subject site is the likely cause �" for the observed distribution of arsenic in soil at the site. The site topography would have directed surface water runoff in northeasterly and easterly directions toward Fanno Creek prior to development of the library facilities. Pre-development topographic contours and associated elevations for the site and 1116 historic aerial photographs were presented in Hahn (2006). The current site layout is shown on Figure 2. The highest concentrations of arsenic detected at the site have been found in the vicinity of the pond. It 106 appears likely that arsenic migrating by overland flow from off-site orchards is the primary source of contamination on the site, based on our review of the available information. The former on-site orchard had little to no impact to arsenic contamination at the site based on predevelopment site topography (sloping to the north and northeast)and the historic location of the on-site orchard (north side of the site). Additional information about on- and off-site orchards was presented by Hahn (2006). wr 4.2 NATURE AND EXTENT OF CONTAMINATION The following sections present a summary of the magnitude and extent of arsenic contamination in soil, sediment, and groundwater, 4.2.1 Soil/Sediment so Soil and sediment are indistinguishable in some areas of the Pinebrook Stream channel and the associated wetland areas. Therefore, soil and sediment are treated as a single contaminated media during the discussion of nature and extent of contamination. Soil and sediment are treated separately during the ecological risk evaluation (Section 5.1.2). Arsenic has been detected in soil/sediment between the ground surface and approximately 7.5 feet bgs at concentrations exceeding the DEQ default background concentration for arsenic (7 milligrams per kilogram [mg/kg]). Figure 6 presents a box plot of arsenic concentrations in soil sorted by depth interval, and Table 2 presents summary statistics for arsenic concentrations by depth interval. Arsenic File No. 4025-003-02 Page 7 GWENGINEERS� July ll,2008 to ,r concentrations that exceed the default background concentration generally occur in the upper 2 to 3 feet of soil/sediment. The highest concentrations of arsenic have been detected in shallow soil near the west and northwest sides of the pond (1 l3 mg/kg in sample "W" collected between the ground surface and l foot bgs) and near the southwest corner of the site (264 mg/kg in sample "12S DUP", collected between the ground surface and 2.8 feet bgs). The area from which sample "12S DUP" was collected is covered by asphalt concrete and is underneath the SW Hall Boulevard ROW. The horizontal and vertical distribution of arsenic generally corresponds to the conceptual site model, whereby, arsenic was transported to the site via overland flow. The approximate extent of arsenic-contaminated soil and past sample locations are shown on Figure 7. �r 4.2.2 Groundwater Arsenic impacts to groundwater are unlikely for several reasons: • The highest concentrations of arsenic are present in near-surface soil. Most of the year, groundwater levels are likely to be more than 3 feet bgs; therefore, groundwater is generally not in contact with the most highly contaminated soil at the site. • Arsenic adsorbs to surfaces of a variety of soil materials, including iron oxides, aluminum oxides, and clay minerals. Aten et al. (1980) report that arsenic is nearly immobile in topsoil, and arsenic in arsenical-pesticide-contaminated topsoil leaches on timescales of decades or more. • The conclusions of Aten et al. (1980) were confirmed by the United States Geological Survey (USGS). The USGS (Hinkle and Pollette, 1999) conducted a survey of arsenic in groundwater in the Willamette Basin (which includes the subject site). One of the primary goals of the survey was to determine if arsenical agricultural chemicals are a significant source of arsenic contamination in groundwater. The USGS concluded that, "regional patterns of arsenic concentrations in ground water of the Willamette Basin as a whole probably reflect primarily natural sources". 4.3 CONTAMINANTS OF INTEREST Arsenic in soil is the only contaminant of interest at the site based on soil analytical data and historical ` uses of the site and surrounding area. HAI (2002) tested soil for other contaminants, including copper, lead, and mercury, organochlorine pesticides, and chlorinated herbicides, none of which were detected at concentrations above natural background (metals) or the laboratory method reporting limits (MRLs). rr 4.4 BENEFICIAL LAND AND WATER USE DETERMINATION ++ The purpose of a beneficial land and water use determination is to provide information regarding the current and reasonably likely future beneficial uses of land and water in the vicinity of a site. Beneficial use determinations provide the basis for the development of exposure scenarios discussed later in this rir section. 4.4.1 Locality of the Facility The locality of the facility (LOF) is defined by DEQ as any point where a human or ecological receptor contacts or is reasonably likely to contact site-related hazardous substances. The LOF takes into account factors such as current site conditions, regional and local hydrogeology, and the likelihood of contaminants migrating over time. FileNo. 4025-003-02 Page 8 GWENGINEERS/ July 11, 2008 The source of most, if not all, of the arsenic contamination at the site appears to be orchards that were historically located west of the site. Thus, the site appears to have been impacted by area-wide contamination. GeoEngineers collected sediment samples in Pinebrook Stream and sediment and surface water samples in the pond in 2008, following the 2007 stream restoration activities, to evaluate whether the site is a significant source of arsenic contamination to Fanno Creek. The soil/sediment and surface water data (discussed in Section 3.5) show that surface water and sediment discharging from the site to Fanno Creek +r are not likely to result in unacceptable risk to ecological receptors in Fanno Creek. Specifically: • Surface water discharging from the pond to Fanno Creek contains very low concentrations of rrr arsenic, even during periods when discharge water contains elevated concentrations of suspended solids. The concentrations of arsenic detected in discharge from the pond are less than DEQ's Level II Screening Level Values (SLVs) for aquatic receptors, indicating that the arsenic in pond discharge water does not pose an unacceptable risk to ecological receptors in Fanno Creek; and • The concentrations of arsenic in mobile sediment (i.e. sediment that was apparently deposited in the lower (east) end of the Pinebrook Stream channel during winter 2007/2008 [samples HA-23 (0-1), HA-24(0-0.5), HA-27(0-0.5), HA-28(0-0.5), HA-29(0-0.5), and HA-30(0-0.5)]) range between non-detect (MRL is 2.8 mg/kg) and 12 mg/kg. The concentrations of arsenic in mobile sediment are within the range of or slightly exceed the DEQ default background concentration for arsenic (7 mg/kg); therefore, it appears that the sediment transported by Pinebrook Stream is not likely to have a significant impact on water and sediment quality in Fanno Creek. Based on our understanding of the source of contamination and the magnitude and extent of IIS contamination, the LOF is limited to the arsenic contaminated soil and sediment within the site property boundaries, the adjacent ROW, and the stream/wetland restoration area. The LOF does not include off- site areas including Fanno Creek and the private property located south of the site. The LOF is shown on rfe Figure 7 4.4.2 Current and Reasonably Likely Future Land Use so GeoEngineers evaluated the current and reasonably likely future land use at the site in general accordance with Oregon DEQ Final Guidance for Consideration of Land Use in Environmental Remedial Actions so (DEQ, 1998a). This evaluation was completed by reviewing the City zoning map, reviewing Murase Associates' "Fanno Creek Park, Master Plan Summary, City of Tigard" (2003), and interviewing Mr. Dennis Koellermeier, Public Works Director for the City. 4.4.2.1 Past Land Use The site historically consisted of vacant land with an orchard at the northern portion of the site. 4.4.2.2 Current Land Use The site is currently occupied by the Tigard library, landscaped and open areas, and parking areas. A pedestrian path is present on the east and north sides of the site. The site is zoned Residential (R-12). The R-12 zoning designation allows residential use, as well as conditional civic and municipal uses. The City has no plans for changing land use at the site. 4.4.2.3 Future Land Use Future land use at the site will remain consistent with current use, according to Murase Associates(2003). File No.4025-003-02 Page 9 GWENGINEERS� July 11,2008 4.4.2.4 Beneficial Land Use Determination The current and likely future land use at the site is a library and associated open and landscaped areas, open to the general public. 4.4.3 Current and Reasonably Likely Beneficial Use of Water GeoEngineers evaluated the current and reasonably likely future beneficial use of water in general �•+ accordance with DEQ Final Guidance for Conducting Beneficial Water Use Determinations at Environmental Cleanup Sites (DEQ 1998b). This evaluation was completed by reviewing water rights information on file with the Oregon Water Resources Department(WRD), U.S. Fish and Wildlife Service wetland maps, and DSL permitting documentation provided by the City. It is unlikely that groundwater at the site has been significantly impacted by arsenic (see Section 4.2.2); therefore, groundwater use was not considered for the beneficial water use determination. •r 4.4.3.1 Surface Water Surface water flows through Pinebrook Stream and the associated wetlands. A pond is located at the southeast corner of the site, north of the restored stream/wetland area. There are no water right surface water points of diversion in Pinebrook Stream or the pond. 4.4.3.2 Wetlands Fanno Creek forms the northern and eastern boundaries of the site and flows south into the Tualatin River, approximately 2 miles south of the site. Wetlands are present near Fanno Creek in the southeastern +r. portion of site. 4.4.3.3 Beneficial Water Use Determination After reviewing relevant information, the following is a summary of our findings: • No surface water right points-of-diversion are located within the LOF. .r� • Wetland areas are present within the LOF. • Pinebrook Stream and the pond are present within the LOF. 4.5 POTENTIAL RECEPTOR-EXPOSURE PATHWAYS The following elements comprise a potentially complete exposure pathway: 1) a chemical source; 2)a mechanism of chemical release to the environment; 3) an environmental transport medium; 4) an exposure point where contact between the contaminated medium and the receptor occurs and 5) an exposure route at the exposure point. A CSM has been developed for the site (Figure 5) and is based on current site use and the results of our beneficial land and water use surveys. Potential receptors and exposure pathways include: • Librarian, maintenance worker, adult and child library/park user, and excavation worker exposure through soil ingestion, dermal contact with soil, and inhalation of soil particulates. ri. • Ecological receptors in undeveloped portions of the site, including the riparian buffer to Fanno Creek, grass covered areas, on-site wetlands, and Pinebrook Stream. rr File No. 4025-003-02 Page 10 GEOENGINEERS� July 11. 2008 5.0 RISK-BASED SCREENING Ilk GeoEngineers evaluated potential risks to human and ecological health by completing screening level human health and ecological risk assessments. The human and ecological health screening assessments are presented in the following sections. Refer to Appendix B for a full discussion of the Level I and Level II ERAS. 5.1 DATA EVALUATION GeoEngineers compiled soil and sediment chemical analytical data collected during all past investigations at the site to develop data sets sufficient to evaluate potential risks to human and ecological health. The compiled data, along with a list of the corresponding risk screening data subsets, are presented in Table 1. I is also present in Microsoft° Excel® format in a CD-ROM, included in Appendix C. The following sections describe the subsets of data that GeoEngineers used to evaluate risks to human and ecological rrF receptors. 5.1.1 Human Health Data Sets to The human health receptors identified in Section 4.5 (librarian, maintenance worker, library/park user, and excavation worker) could be exposed to different contaminated soil areas or depth intervals at the site. Therefore, the soil data set was divided into the following data subsets for human health risk screening: 5.1.1.1 Surface Soil (librarian, maintenance worker, library/park user): „ • Soil between 0 and 3 feet bgs (207 samples). This data set includes: 1) samples that represent soil remaining in-place with no existing or proposed pavement, soil or mulch cap and 2) samples that represent soil remaining in-place with a soil cap less than 2 feet thick. Samples that represent soil that is covered by asphalt/concrete(parking areas, pathways, sidewalks, and the building) and samples collected within the pond were not included in this data set. 5.1.1.2 All Soil (excavation worker): • Soil between 0 and 7.5 feet bgs (324 samples). This data set includes all samples that represent soil remaining at the site, regardless, of whether the samples are covered with concrete/asphalt pavement or are submerged in the pond. Samples that were collected at different depths from a single location were evaluated as discrete values in the data sets. 5.1.2 Ecological Data Sets Ecological receptors that could be exposed to contaminants at the site include terrestrial and aquatic irri receptors. Data used for the ecological risk-based screening process were limited to: 1) samples that represent soil remaining in-place with no existing or proposed pavement, soil or mulch cap and 2) samples that represent soil left in-place with a soil cap less than 2 feet thick. Terrestrial and aquatic receptors could be exposed to contaminants in different areas of the site; therefore, the soil/sediment data set was divided into the following data subsets for ecological health risk screening: File No.4025-003-02 Page 11 GWENGINEER� July 11,2008 r 5.1.2.1 Terrestrial Soil (plants, invertebrates, birds, and mammals): • Soil between 0 and 3 feet bgs (207 samples). This data set includes samples collected from surface soil/sediment from the entire site, with the exception of samples collected in the pond. 5.1.2.2 Aquatic Soil/Sediment (freshwater sediment, bioaccumulation, probable effects concentration): • Soil/sediment between 0 and 2 feet bgs (41 samples). This data set includes surface soil/sediment samples within the wetland restoration area and pond. The submerged areas of the Pinebrook Stream channel can vary significantly seasonally, therefore, sample data collected throughout the Pinebrook Stream/wetland restoration area and pond were used to evaluate the risks posed by arsenic in sediment. AM Samples that were collected at different depths from a single location were evaluated as discrete values in the data sets. The terrestrial and aquatic areas described above are shown on Figure 6. to 5.1.3 Calculation of Exposure Point Concentrations and Environmental Concentrations GeoEngineers calculated exposure point concentrations (EPCs) to evaluate risks to human health and environmental concentrations (ECs) to evaluate risks to ecological health. The EPC and EC calculations are described below. EPCs and ECs are, in some cases, determined based on upper confidence levels (UCLs), which are statistical estimations of the arithmetic mean concentration of a chemical in the environment and are calculated based on the statistical distribution of a data set. The 90 percent UCL represents the value below which the true arithmetic mean is expected to fall with 90 percent certainty. GeoEngineers calculated UCLs using U.S. Environmental Protection Agency (EPA) ProUCL© version 4.00.02 software (EPA, 2008). The method used to calculate the UCL was selected based on ProUCL's recommended to method for calculating the 95 percent UCL (ProUCL does not provide a recommendation for calculating the 90 percent UCL). WO 5.1.3.1 Exposure Point Concentrations GeoEngineers calculated EPCs for arsenic in soil to assess potential risks to human health. An EPC represents a reasonable estimate of the maximum concentration of arsenic that a human may be exposed to at the site. EPCs were determined by selecting the lesser of either: 1) the 90th percent upper 9Mto limit of the arithmetic mean; or 2) the maximum detected concentration (MDC) for each data set. to 5.1.3.2 Environmental Concentrations GeoEngineers calculated ECs for arsenic in soil and sediment to assess potential risks to ecological health. The EC is either: I) the MDC (for plants and invertebrates); or 2) the lesser of the 90 percent • UCL or the MDC (for birds, mammals, and for the evaluation of the Pinebrook Stream/wetland area). 5.2 HHRA RESULTS As noted in Section 4.3, arsenic in soil is the only COI. GeoEngineers calculated EPCs for the soil data sets described in Section 5.1.1. GeoEngineers compared the EPCs to site-specific risk-based concentrations (RBCS) for occupational workers (librarians and maintenance workers) and library/park users and to DEQ's generic RBC for excavation workers to assess potential human health risks. Table 3 presents the EPCs and RBCs for the human health risk assessment. r r. File No. 4025-003-02 Page 12 GWENGINEER� July 11,2008 5.2.1 Exposure Assumptions and RBCs The site-specific exposure assumptions for each potential receptor, the rationale for choosing the site- specific values, and the corresponding arsenic RBCs are described below. RBCs were calculated based on a cancer risk of l x 10-6, which is defined by OAR 340-122-115 as the acceptable risk level for individual carcinogens. Librarian: Exposure assumptions for this receptor are default DEQ occupational worker values with the exception of exposure frequency. It was assumed that the librarians (and other library employees) would spend most of their time inside of the library and that exposure to site soils would be limited. An exposure frequency of 52 days per year(or 1 day per week) was selected to evaluate the potential for the library employees to be exposed to site soils during periods outside of the library building. The arsenic RBC for the Librarian is 8.3 mg/kg. Maintenance Worker: This exposure scenario evaluates persons responsible for maintaining the library facilities, including landscaping. The exposure assumptions are a combination of site-specific exposure frequency and default DEQ occupational and excavation/construction worker values. An exposure frequency of 12 days per year (or I day per month), a soil ingestion rate of 330 mg/day, an adherence Na factor of 0.3 mg/cm2-day, and exposure duration of 25 years were selected for this receptor. The soil ingestion rate and adherence factor are the default values for construction and excavation workers. The rational for the higher soil ingestion rate and adherence factor is that the maintenance workers are am assumed to have more direct contact with soil during weeding or planting. The exposure duration is the default value for occupational workers. The arsenic RBC for the Maintenance Worker is 1 I mg/kg. Adult and Child Park Users: Exposure assumptions for this receptor are default DEQ residential values with the exception of exposure frequency. An exposure frequency of 52 days per year (or 1 day per week) was selected to represent reasonable maximum exposure to site soils. This exposure scenario , would cover library visitors that use the park during their visits to the library and neighbors using the park or pedestrian path. The arsenic RBC for the Adult and Child Park Users is 2.6 mg/kg. DEQ's default background concentration for arsenic in soil is 7 mg/kg. , Excavation Worker: The exposure assumptions are default DEQ excavation worker values. This scenario would cover instances when excavation activities would necessitate exposure to contaminated subsurface soils. The arsenic RBC for the Excavation Worker is 370 mg/kg. 5.2.2 Risk Characterization ft Carcinogenic risks were estimated for each receptor by dividing the arsenic EPC by the receptor-specific RBC and multiplying this ratio by the acceptable risk level of 1 x 10-6 to compute the risk estimate, as follows (DEQ, 2000): Risk=(EPC/RBC) x(1 x 10-6) Where: • EPC = Exposure point concentration in mg/kg. • RBC= Risk-based concentration in mg/kg. File No. 4025-003-02 Page 13 GWENGINEERS/ July 11,2008 AN Ar Librarian: The estimated carcinogenic risk for the librarian, based on exposure to surface soil, is I x10-6. This estimate is equal to the DEQ acceptable risk level of l x 10-6 for individual carcinogens. Maintenance Worker: The estimated carcinogenic risk for the maintenance worker, based on exposure ' to surface soil, is l x 10-6. This estimate is equal to the DEQ acceptable risk level of I x 10-6 for individual carcinogens. Adult and Child Park User: The estimated carcinogenic risk for the adult and child park user, based on exposure to surface soil, is 5 x 10-6. This estimate exceeds the DEQ acceptable risk level of 1 x 10-6 for individual carcinogens. .r Excavation Worker: The estimated carcinogenic risk for the excavation worker, based on exposure to surface soil, is 3 x 10-8. This estimate is well below the DEQ acceptable risk level of 1 x 10-6 for individual carcinogens. 5.2.3 Summary ,.r The carcinogenic risk estimates for occupational receptors (librarian, maintenance worker, and excavation worker) are equal to or less than DEQ's acceptable risk level of 1 x 10-6 for individual carcinogens. These estimates indicate that the concentrations of arsenic in soil do not present an unacceptable risk to librarians, maintenance workers, or excavation workers. The estimated carcinogenic risk for park users (adults and children) exceed DEQ's acceptable risk level of 1 x 10-6 for individual carcinogens. The extent of soil that contains arsenic at concentrations exceeding both the RBC for park users and the background concentration (excluding the restoration and pond areas and areas with an existing or proposed cap) are shown in Figure 6. 5.3 ERA RESULTS The ecological risk assessment (ERA), consisting of Level I and Level II ERAs, was completed to assess potential risks to ecological receptors from contaminants in soil/sediment within the LOF. The Level I ERA was completed to assess the LOF for suitability of habitat for threatened and endangered (T&E) species and other species, and the Level II ERA was completed to assess the risks to these species from .r arsenic in soil and sediment within the LOF. The conclusions of the ERAs are presented below and the complete Level I and II ERAs are presented in Appendix B. Sensitive habitat (wetlands and riparian buffer) and potentially complete receptor-contaminant exposure pathways were identified within the LOF, based on the results of the Level I ERA. Ecological receptors that may utilize habitat within the LOF and become exposed to arsenic in soil/sediment include both terrestrial species (plants, mammals, birds and other terrestrial organisms) and aquatic species (fish, plants, and aquatic invertebrates within the Pinebrook Stream channel and the pond). Species of special concern, including two species of T&E fish, were identified within a 2-mile radius of the site (ONHIC, 2006). With the exception of the Northern Pacific pond turtle (a non-T&E species), suitable habitat for species of special concern, as identified by ONHIC, does not exist within the LOF. An on-site survey of the Northern Pacific pond turtle was not conducted as part of this ERA; however,the r► pond turtle is known not to occur within the LOF under normal conditions. rw GMENGINEERS� File No. 4025-003-02 Page 14 July 11, 2008 r�r 5.3.1 Terrestrial Evaluation Results of the Level II ERA show that arsenic in soil is not a concern to terrestrial ecological receptors with the exception of non-T&E plants. Arsenic may be a terrestrial contaminant of potential ecological concern (OPEC) because the EC (based on the maximum detected concentration of arsenic in soil [113 mg/kg]) exceeds the DEQ Level II Screening Level Value (SLV) for non-T&E plants(50 mg/kg). The site-wide average (90 percent UCL) concentration of arsenic (11.9 mg/kg) does not exceed the DEQ Level I1 SLV for non-T&E plants. 5.3.2 Aquatic Evaluation Arsenic is an aquatic CPEC within the Pinebrook Stream channel because the arsenic EC within the stream channel (33.4 mg/kg, based on the 90 percent UCL) exceeds the DEQ freshwater sediment Level II Screening Level Value (SLV) of 6 mg/kg and the sediment bioaccumulation SLV of 7 mg/kg (DEQ, 1998). The freshwater sediment SLV and the sediment bioaccumulation SLV were used to evaluate sediment within the proposed stream bed. Areas in the restoration and pond area where arsenic concentrations exceed the freshwater sediment and sediment bioaccumulation SLVs are shown in Figure 6. Arsenic was not identified as an aquatic CPEC in areas outside of the stream channel, but within the rr restoration area, based on an evaluation of the soil to sediment exposure pathway. The arsenic EC for this exposure pathway within the restoration area, based on the 90 percent UCL of 33.4 mg/kg, is equal to the PEC of 33 mg/kg (DEQ, 2005). Therefore, arsenic is not a CPEC for soils adjacent to the stream channel ob (i.e., within the wetland area and the stream bank). 6.0 CONCLUSIONS It does not appear that significant concentrations of arsenic are migrating off-site through discharge from either the pond or Pinebrook Stream; however, arsenic in soil/sediment at portions of the site could pose an unacceptable risk to human and ecological health. Mitigation, including capping, excavation, institutional controls, and/or engineering controls are recommended to reduce the risks from exposure to arsenic in soil. GeoEngineers, in consultation with the City and DEQ, will prepare a focused feasibility study and a remedial action plan to address risks posed by arsenic contamination in soil. 7.0 REFERENCES Apex Environmental Consulting Services Inc. September 16, 2003. Arsenic Contaminated Soils Removal Close Out Report/Work Plan Update For the New City of Tigard Library Site. Aten, C.F., Bourke, J.B., Martini, J.H., and Walton, J.C., 1980, Arsenic and lead in an orchard rrr environment: Bulletin of Environmental Contamination and Toxicology, v. 24, p. 108-115. GeoEngineers, Inc., July 12, 2007. April 2007 Soil Assessment,Tigard Library, Tigard, Oregon. GeoEngineers, Inc., March 11, 2008. Revised Construction Summary Report, Tigard Library, Tigard, Oregon. File No.4025-003-02 Page 15 GmENGINEER� July 11,2008 wr .r Hahn Associates, Inc, December 2, 2002. Phase II Environmental Site Assessment Report, 14.7 Acre Property, 13360 and 13560 SW Hall Boulevard, Tigard, Oregon. Hahn Associates, Inc, October 6, 2006. Draft Supplemental Site Investigation Report. .r Hinkle, S.R. and Polette, D.J. 1999. United States Geological Survey Water-Resources Investigations Report 98-4205, Arsenic in Ground Water of the Willamette Basin, Oregon. Murase Associates, 2003. Fanno Creek Park Master Plan, City of Tigard. .Ar Oregon Department of Environmental Quality, 1998. Gudance for Conduct of Deterministic Human Health Risk Assessments—Updated May 2000. �. Oregon Department of Environmental Quality, 1998. Guidance for Ecological Risk Assessment, Level I Scoping, Level 11 Screening (Updated December 2001), Level II Screening Benchmark Values. Waste Management and Cleanup Division. Oregon Department of Environmental Quality, 2002. Default Background Concentration for Metals, October 2002. Oregon Department of Environmental Quality, 1998a. Final Guidance for Consideration of Land Use in Environmental Remedial Actions July 1, 1998. rr Oregon Department of Environmental Quality, 1998b. Final Guidance for Conducting Beneficial Water Use Determinations at Environmental Cleanup Sites. July I, 1998. Oregon Deparment of Environmental Quality/US Environmental Protection Agency, 2005. Portland Harbor Joint Source Control Strategy. December 2005. .r Oregon Water Resources Department (OWRD), 2004. Oregon Water Resources Department GRID Web Query Application and Water Rights Maps. http://www.wrd.state.or.us/ dW Shannon and Wilson, 2003. Geotechnical Investigation, Wall Street LID, Tigard, Oregon. United States Environmental Protection Agency(EPA), 2008. ProUCL Software, Version 4.00.02. +� United States Fish and Wildlife Service (USFWS), 2004. United States Fish and Wildlife Service Wetlands Mapper(http://wetlandsfws.er.usgs.gov). do ro rir rrr File No.4025-003-02 Page 16 GEOENGINEERS July 11,2008 TABLE 1 SOIL ANALYTICAL RESULTS TIGARD LIBRARY 13500 SW HALL BOULEVARD J TIGARD, OREGON Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Pre-Development Testing(2002,2003) Uplands 003 020905-003 09/04/98 0.25 - 1.5 HAI In-Place No Cap 18.7 Yes Yes Yes No Uplands 004 020905-004 09/04/98 0.25 - 1.5 HAI In-Place No Cap 26.1 Yes Yes Yes No Uplands 009 020905-009 09/04/98 0.25 - 1.5 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands 010 020905-010 09/04/98 0.25 - 1.5 HAI In-Place No Cap 2.64 Yes Yes Yes No Uplands 011 020905-001, -002 09/04/98 0.25 - 1.5 HAI In-Place No Cap 2.83 Yes Yes Yes No (composite) 020905-003, -004 Uplands 012 , 09/04/98 0.25 - 1.5 HAI In-Place No Cap 21.5 No' NoNoNo' (composite) Uplands 013 020905-005, -006 09/04/980.25 - 1.5 HAI 006 Removed Removed 9.07 No No No No (composite) Uplands 014 020905-007, -008 09/04/98 0.25 - 1.5 HAI In-Place No Cap 2 U Yes Yes Yes No (composite) Uplands SS-1 030108-015 01/07/99 0.0 - 0.25 HAI Removed Removed 10.7 No No No No Uplands SS-1 030108-016 01/07/99 0.25 - 0.5 HAI Removed Removed 4.41 No No No No Uplands SS-1 030108-017 01/07/99 0.5 - 0.75 HAI Removed Removed 64.6 No No No No [ Uplands SS-1 030108-018 01/07/09 0.75 - 1.0 HAI Removed Removed 3.37 No No No No I! Uplands SS-1 030108-019 01/07/99 1.0 - 1.5 HAI Removed Removed 4.94 No No No No Uplands SS-1 030108-020 01/07/99 1.5 - 2.0 HAI Removed Removed 17.4 No No No No Uplands SS-1 030108-021 01/07/99 2.0 - 2.5 HAI In-Place Ca - Paved 1.85 U No Yes No No Uplands SS-1 030108-022 01/07/99 2.5 - 3.0 HAI In-Place Ca - Paved 2 U No Yes No No Uplands SS-2 030108-023 01/07/99 0.0 - 0.25 HAI In-Place No Cap 2.41 Yes Yes Yes No Uplands SS-2 030108-024 01/07/99 0.25 - 0.5 HAI In-Place No Cap 4.42 Yes Yes Yes No Uplands SS-2 030108-025 01/07/99 0.5 - 0.75 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands SS-2 030108-026 01/07/99 0.75 - 1.0 HAI In-Place No Cap 5.41 Yes Yes Yes No Uplands SS-2 030108-027 01/07/99 1.0 - 1.5 HAI In-Place No Cap 5.16 Yes Yes Yes No Uplands SS-2 030108-028 01/07/99 1.5 - 2.0 HAI In-Place No Cap 10.2 Yes Yes Yes No Uplands SS-2 030108-029 01/07/99 2.0 - 2.5 HAI In-Place No Cap 1.85 U Yes Yes Yes No Uplands SS-2 030108-030 01/07/99 2.5 - 3.0 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands SS-3 030206-031 02/05/99 0.0 - 1.0 HAI In-Place No Cap 2.08 U Yes Yes Yes No Uplands SS-4 030206-033 02/05/99 0.0 - 1.0 HAI Removed Removed 33.3 No No No No Uplands SS-4 030206-034 02/05/99 1.0 - 2.0 HAI In-Place2 Cap- Soil/Paved 15.7 No Yes No No Uplands SS-5 030206-035 02/05/99 0.0 - 1.0 HAI In-Place Ca Paved 2 U No Yes No No Uplands SS-6 030206-037 02/05/99 0.0 - 1.0 HAI In-Place Ca - Soil 1.85 U No Yes No No Uplands SS-7 030206-039 02/05/99 0.0 - 1.0 HAI In-Place No Cap 11 Yes Yes Yes No Uplands SS-7 030206-040 02/05/99 1.0 - 2.0 HAI In-Place No Cap 11.2 Yes Yes Yes No Uplands SS-8 030207-041 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 2.12 No Yes No No Uplands SS-9 030207-043 02/06/99 0.0 - 1.0 HAI Removed Removed 12.2 No No No No Uplands SS-9 030207-044 02/06/99 1.0 - 2.0 HAI In-Place Ca - Paved 2.76 No Yes No No Uplands SS-10 030207-045 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.85 U No Yes No No Uplands SS-11 030207-047 02/06/99 0.0 - 1.0 HAI In-Place No Cap 1.72 U Yes Yes Yes No Uplands SS-12 030207-049 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.85 U No Yes No No File No. 4025-003-02 Table 1,July 11,2008 Page 1 of 9 GWENGINEER Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Uplands SS-13 030207-051 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 2.94 No Yes No No Uplands SS-14 030207-053 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 6.84 No Yes No No Uplands SS-15 030207-055 02/06/99 0.0 - 1.0 HAI Removed Removed 36.6 No No No No Uplands SS-15 030207-056 02/06/99 1.0 - 2.0 HAI Removed Removed 15.4 No No No No Uplands SS-16 030207-057 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 4.24 No Yes No No Up lands SS-17 030207-059 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 2.16 No Yes No No Uplands SS-18 030207-061 02/06/99 0.0 - 1.0 HAI In-Place No Cap 1.85 U Yes Yes Yes No Uplands SS-19 030207-063 02/06/99 0.0 - 1.0 HAI In-Place No Cap 1.92 U Yes Yes Yes No Uplands SS-20 030207-065 02/06/99 0.0 - 1.0 HAI In-Place No Cap 2.26 Yes Yes Yes No Uplands SS-21 030207-067 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.85 U No Yes No No Uplands SS-22 030207-069 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.92 U No Yes No No Uplands SS-23 030207-071 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.85 U No Yes No No Uplands SS-23 030207-072 02/06/99 1.0 - 2.0 HAI In-Place Ca - Paved 1.92 U No Yes No No Uplands SS-24 030207-073 02/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 4.46 No Yes No No Uplands SS-25 030207-075 02/06/99 0.0 - 1.0 HAI Removed Removed 23.4 No No No No Uplands SS-25 030207-076 02/06/99 1.0 - 2.0 HAI Removed Removed 8.89 No No No No Uplands SS-26 030207-077 02/06/99 0.0 - 1.0 HAI In-Place No Cap 8.74 Yes Yes Yes No Uplands SS-26 030207-078 02/06/99 1.0 - 2.0 HAI In-Place No Cap 4.59 Yes Yes Yes No Uplands SS-27 030207-079 02/06/99 0.0 - 1.0 HAI In-Place No Cap 1.85 U Yes Yes Yes No Uplands SS-28 030209-081 02/08/99 0.0 - 1.0 HAI In-Place No Cap 2.23 Yes Yes Yes No Uplands SS-29 030209-083 02/08/99 0.0 - 1.0 HAI In-Place No Cap 4.85 Yes Yes Yes No Uplands SS-30 030209-085 02/08/99 0.0 - 1.0 HAI In-Place No Cap 1.98 Yes Yes Yes No Uplands SS-31 030209-087 02/08/99 0.0 - 1.0 HAI In-Place No Cap 1.85 U Yes Yes Yes No Uplands SS-32 030209-089 02/08/99 0.0 - 1.0 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands SS-32 030209-090 02/08/99 1.0 - 2.0 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands SS-33 030209-091 02/08/99 0.0 - 1.0 HAI In-Place No Cap 1.85 U Yes Yes Yes No Uplands SS-33 030209-092 02/08/99 1.0 - 2.0 HAI In-Place No Cap 1.92 U Yes Yes Yes No Uplands SS-34 030209-093 02/08/99 0.0 - 1.0 HAI In-Place No Cap 2.06 Yes Yes Yes No Uplands SS-34 030209-094 02/08/99 1.0 - 2.0 HAI In-Place No Cap 2.08 U Yes Yes Yes No Uplands SS-35 030209-095 02/08/99 0.0 - 1.0 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands SS-36 030209-097 02/08/99 0.0 - 1.0 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands SS-37 030408-139 04/07/99 0.0 - 1.0 HAI Removed Removed 17.8 No No No No Uplands SS-38 030408-140 04/07/99 0.0 - 1.0 HAI Removed Removed 11 No No No No Uplands SS-39 030408-141 04/07/99 0.0 - 1.0 HAI In-Place No Cap 1.85 U Yes Yes Yes No Restoration Area SS-40 030408-142 04/07/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.92 U No Yes No No Restoration Area SS-41 030408-143 04/07/99 0.0 - 1.0 HAI In-Place No Cap 2.08 U Yes Yes Yes Yes Uplands SS-42 030408-138 04/07/99 0.0 - 1.0 HAI Removed Removed 29.6 No No No No Uplands SS-43 030408-136 04/07/99 0.0 - 1.0 HAI Removed Removed 10.7 No No No No Uplands SS-44 030408-133 04/07/99 0.0 - 1.0 HAI Removed Removed 14.5 No No No No Uplands SS-44 030408-134 04/07/99 1.0 - 2.0 HAI Removed Removed 6.47 No No No No Uplands SS-44 030408-135 04/07/99 2.0 - 3.0 HAI In-Place2 Cap- Soil/Paved 10.2 No Yes No No Uplands SS-45 030408-131 04/07/99 0.0 - 1.0 HAI In-Place Cap - Paved 7.74 No Yes No No Restoration Area SS-46 030408-129 04/07/99 0.0 - 1.0 HAI In-Place No Cap 10.2 Yes Yes Yes Yes Uplands SS-47 030408-121 04/07/99 0.0 - 1.0 HAI Removed Removed 9.36 No No No No Uplands SS-48 030408-122 04/07/99 0.0 - 1.0 HAI Removed Removed 107 No No No No Uplands SS-48 030408-123 04/07/99 1.0 - 2.0 HAI Removed Removed 48.2 No No No No Uplands SS-49 030408-124 04/07/99 0.0 - 1.0 HAI Removed Removed 4.15 No No No No Uplands SS-50 1 030408-126 04/07/99 0.0 - 1.0 HAI In-Place No Cap 4.72 Yes Yes Yes No Uplands SS-5U 030408-128 04/07/99 0.0 - 1.0 HAI In-Place No Cap 3.89 Yes Yes Yes No Uplands SS-52 1 030407-120 04/06/99 0.0 - 1.0 HAI In-Place No Cap 7.62 Yes Yes Yes No File No.4025-003-02 Table 1,July 11,2008 Page 2 of 9 GEOENGINEERS� Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Uplands SS-53 030407-110 04/06/99 0.0 - 1.0 HAI Removed Removed 7.83 No No No No Uplands SS-54 030407-111 04/06/99 0.0 - 1.0 HAI Removed Removed 27.3 No No No No Uplands SS-54 030407-112 04/06/99 1.0 - 2.0 HAI Removed Removed 31.4 No No No No Uplands SS-55 030407-113 04/06/99 0.0 - 1.0 HAI Removed Removed 22 No No No No Uplands SS-55 030407-114 04/06/99 1.0 - 2.0 HAI Removed Removed 8.2 No No No No Uplands SS-55 030407-115 04/06/99 2.0 - 3.0 HAI In-Place Ca - Soil/Paved 5.68 No Yes No No Uplands SS-56 030407-116 04/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 4.57 No Yes No No Uplands SS-57 030407-118 04/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 3.23 No Yes No No Uplands SS-58 030407-119 04/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 2.26 No Yes No No Uplands SS-59 030407-108 04/06/99 0.0 - 1.0 HAI Removed Removed 91.3 No No No No Uplands SS-59 030407-109 04/06/99 1.0 - 2.0 HAI Removed Removed 18.4 No No No No Uplands SS-60 030407-106 04/06/99 0.0 - 1.0 HAI In-Place Ca (Proposed) 8.02 No Yes No No Uplands SS-61 030407-104 04/06/99 0.0 - 1.0 HAI In-Place Ca (Proposed) 7.38 No Yes No No Uplands SS-62 030407-103 04/06/99 0.0 - 1.0 HAI In-Place Ca (Proposed) 3 No I Yes No No Uplands SS-63 030407-102 04/06/99 0.0 - 1.0 HAI In-Place No Cap 6.75 Yes Yes Yes No Uplands SS-64 030407-099 04/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 4.17 No Yes No No Uplands SS-65 030407-100 04/06/99 0.0 - 1.0 HAI Removed Removed 6.71 No No No No Uplands I SS-66 1 030407-101 1 04/06/99 0.0 - 1.0 HAI In-Place Ca - Paved 1.92 U No Yes No No Apex Confirmation Samples 2003 Uplands is is 07/16/99 0.0 - 1.0 Apex Removed Removed 14 No No No No Uplands is 4S 07/20/99 0.0 - 2.0 Apex In-Place Ca -Soil 4.8 No Yes No No Uplands 2S 2S 07/16/99 0.0 - 2.0 Apex In-Place Ca - Paved 4 No Yes No No Uplands 3S 3S 07/16/99 0.0 - 2.0 Apex In-Place Ca - Paved 5 No Yes No No Uplands 5S 5S 07/20/99 0.0 - 1.5 Apex In-Place Ca -Soil/Paved 6 No Yes No No Uplands 6S 6S 07/21/99 0.0 - 1.5 Apex Removed Removed 8 No No No No Uplands 6S 12S 07/24/99 0.0 - 2.8 Apex In-Place Ca - Paved 110 No Yes No No Uplands 6S 12S Du 07/24/99 0.0 - 2.8 Apex In-Place Ca - Paved 264 No Yes No No Uplands 7S 7S 07/21/99 0.0 - 1.5 Apex Removed Removed 10 No No No No Uplands 7S 14S 07/24/99 0.0 - 2.8 Apex In-Place Ca - Soil 2 No Yes No No Uplands 8S 8S 07/23/99 0.0 - 1.5 Apex In-Place Ca - Paved 6 No Yes No No Uplands 9S 9S 07/23/99 0.0 - 1.5 Apex Removed Removed 41 No No No No Uplands 9S 24S 07/29/99 0.0 - 2.3 Apex In-Place2 Cap- Paved 25 No Yes No No Uplands 9S 29S 07/31/99 1.0 3 Apex In-Place Cap- Paved 1.7 No Yes No No Uplands 10S 10S 07/24/99 0.0 - 1.5 Apex Removed Removed 21 No No No No Uplands 10S 19S 07/28/99 0.0 - 2.5 Apex In-Place Ca -Soil 6.5 No Yes No No Uplands lis 11S 07/24/99 0.0 - 2.5 Apex Removed Removed 15 No No No No Uplands 11S 23S 07/29/99 0.0 - 3.3 Apex In-Place2 Cap- Soil 11 No Yes No No Uplands 11S 28S 07/31/99 1.0 3 Apex In-Place Cap -Soil 3.4 No Yes No No Uplands 13S 13S 07/24/99 0.0 - 1.7 Apex In-Place Ca - Paved 4 No Yes No No Uplands 15S 15S 07/24/99 0.0 - 1.5 Apex In-Place Ca - Soil 3 No Yes No No Uplands 16S 16S 07/27/99 0.0 - 1.5 Apex Removed Removed 9.7 No No No No Uplands 16S 20S 07/29/99 0.0 - 1.5 Apex In-Place Cap - Paved 6.1 No Yes No No Uplands 17S 17S 07/27/99 0.0 - 1.5 Apex Removed Removed 32 No No No No Uplands 17S 21S 07/29/99 0.0 - 1.5 Apex In-Place Ca - Paved 2.5 No Yes No No Uplands 18S 18S 07/27/99 0.0 - 1.5 -Apex Removed Removed 7.4 No No No No Uplands 18S 22S 07/29/99 0.0 - 1.5 Apex In-Place Ca - Paved 5.9 No Yes No No Uplands 25S 25S 07/29/99 0.0 - 2.5 Apex In-Place Ca - Soil 5.4 No Yes No No Uplands 26S 26S 07/29/99 0.0 - 1.5 Apex In-Place Ca (Proposed) 6.4 No Yes No No Uplands 27S 27S 07/29/99 0.0 - 1.5 Apex In-Place Ca - Paved 6.6 No Yes No No Restoration Area 30S 30S 08/13/99 0.0 - 1.5 Apex In-Place No Cap 6 Yes Yes Yes Yes File No.4025-003-02 Table 1,July 11,2008 Page 3 of 9 GEOENGINEERS� i II Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Restoration Area 31S 31S 08/13/99 0.0 - 1.5 Apex In-Place No Cap 2 Yes Yes Yes Yes Restoration Area 32S 32S 08/13/99 0.0 - 1.5 Apex In-Place No Cap 7 Yes Yes Yes Yes Uplands 004 004 07/24/99 0.5 Apex In-Place Ca - Paved 13 No Yes No No Uplands 005 005 07/24/99 0.5 Apex In-Place No Cap 8 Yes Yes Yes No Uplands 006 006 07/24/99 0.5 Apex In-Place No Cap 7 Yes Yes Yes No Uplands 007 007 07/24/99 0.5 Apex In-Place No Ca 2 Yes Yes Yes No Uplands 008 008 07/24/99 0.5 Apex In-Place No Cap 2 Yes Yes Yes No Bike Path Investi ation 2005 Uplands S1 S1 a 09/22/01 0.0 - 0.5 HAI In-Place No Ca 2 U Yes Yes Yes No Uplands S1 S1 b 09/22/01 0.5 - 1.5 HAI In-Place No Ca 3.14 Yes Yes Yes No Uplands S1 S1 c 09/22/01 1.5 - 2.0 HAI In-Place No Ca 2 U Yes Yes Yes No Uplands S2 S2a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 4.5 Yes Yes Yes No Uplands S2 S2b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 4.13 Yes Yes Yes No Uplands S2 S2c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 2 U Yes Yes Yes No Uplands S3 S3a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 4.19 Yes Yes Yes No ` Uplands S3 S3b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 2.88 Yes Yes Yes No Uplands S3 S3c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 3.05 Yes Yes Yes No Uplands S4 S4a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 1.79 U Yes Yes Yes No Uplands S4 S4b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 6.27 Yes Yes Yes No Uplands S4 S4c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 1.82 U Yes Yes Yes No Uplands S5 S5a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 5.33 Yes Yes Yes No Uplands S5 S5b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 5.35 Yes Yes Yes No Uplands S5 S5c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 6.92 Yes Yes Yes No Uplands S6 S6a 09/22/01 0.0 - 0.5 HAI Removed Removed 9.05 No No No No Uplands S6 S6b 09/22/01 0.5 - 1.5 HAI Removed Removed 17.2 No No No No Uplands S6 S6c 09/22/01 1.5 - 2.0 HAI Removed Removed 11.3 No No No No Uplands S6 S14-2025 10/12/01 2.0 - 2.5 HAI Removed Removed 7.45 No No No No Uplands S6 S14-2530 10/12/01 2.5 - 3.0 HAI In-Place Ca - Paved 6.17 No Yes No No Uplands S7 S7a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 3.71 Yes Yes Yes No Uplands S7 S7b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 3.03 Yes Yes Yes No Uplands S7 S7c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 2.88 Yes Yes Yes No Uplands S8 S8a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 3.39 Yes Yes Yes No Uplands S8 S8b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 3.13 Yes Yes Yes No Uplands S8 S8c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 2.65 Yes Yes Yes No Uplands S9 S9a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 4.56 Yes Yes Yes No Uplands S9 S9b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 5.41 Yes Yes Yes No Uplands S9 S9c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 5.01 Yes Yes Yes No Uplands S10 S1 Oa 09/22/01 0.0 - 0.5 HAI In-Place No Cap 2.44 Yes Yes Yes No Uplands S10 S1 Ob 09/22/01 0.5 - 1.5 HAI In-Place No Cap 4.49 Yes Yes Yes No Uplands S10 S10c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 4.14 Yes Yes Yes No Uplands S11 S11a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 2.58 Yes Yes Yes No Uplands S11 S11 b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 3.52 Yes Yes Yes No Uplands S11 S11c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 3.59 Yes Yes Yes No Uplands S12 S1 2a 09/22/01 0.0 - 0.5 HAI In-Place No Cap 3.08 Yes Yes Yes No Uplands S12 _S1 2b 09/22/01 0.5 - 1.5 HAI In-Place No Cap 4.2 Yes Yes Yes No Uplands S12 S1 2c 09/22/01 1.5 - 2.0 HAI In-Place No Cap 2.86 Yes Yes Yes No Uplands S13 S1 3a 09/22/01 0.0 - 0.5 HAI In-Place Ca - Paved 5.32 No Yes No No Uplands S13 S13b 09/22/01 0.5 - 1.5 HAI In-Place Ca - Paved 8.46 No Yes No No Uplands S13 S17-0515 10/12/01 0.5 - 1.5 HAI In-Place Ca - Paved 8.58i-I No Yes No No Uplands S13 S1 3c 09/22/01 1.5 - 2.0 HAI In-Place Ca - Paved 6.5 No Yes No No File No. 4025-003-02 Table 1,July 11,2008 Page 4 of 9 GWENGINEER� Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Uplands S15 S15-010 10/12/01 0.0 - 1.0 HAI Removed Removed 13.3 No No No No Uplands S15 S15-1020 10/12/01 1.0 - 2.0 HAI Removed Removed 5.96 No No No No Uplands S15 S15-2025 10/12/01 2.0 - 2.5 HAI Removed Removed 8.15 No No No No Uplands S15 S15-2530 10/12/01 2.5 - 3.0 HAI In-Place Ca - Paved 4.33 No Yes No No Uplands S16 S16-010 10/12/01 0.0 - 1.0 HAI Removed Removed 23.8 No No No No Uplands S16 S16-1020 10/12/01 1.0 - 2.0 HAI Removed Removed 28.6 No No No No Uplands S16 S16-2025 10/12/01 2.0 - 2.5 HAI Removed Removed 29 No No No No Uplands S16 S16-2530 10/12/01 2.5 - 3.0 HAI Removed Removed 20.8 No No No No Uplands S16 S16-3035 10/12/01 3.0 - 3.5 HAI Removed Removed 11 No No No No Uplands S16 S1 6-B 11/10/01 3.0 - 3.5 HAI In-Place Ca - Paved 2.55 No Yes No No Uplands S18 S18-010 10/12/01 0.0 - 1.0 HAI In-Place No Cap 6.58 Yes Yes Yes No Uplands S18 S18-1020 10/12/01 1.0 - 2.0 HAI In-Place No Cap 6.85 Yes Yes Yes No Uplands S18 S18-2030 10/12/01 2.0 - 3.0 HAI In-Place No Cap 4.14 Yes Yes Yes No Uplands S19 S19-010 10/12/01 0.0 - 1.0 HAI Removed Removed 23.9 No No No No Uplands S19 S19-1020 10/12/01 1.0 - 2.0 HAI Removed Removed 3.21 No No No No Uplands S19 S19-2030 10/12/01 2.0 - 3.0 HAI Removed Removed 16.9 No No No No Uplands S19 S1 9-13 11/10/01 3.0 - 3.5 HAI In-Place Ca - Paved 2.68 No Yes No No Site-Wide Supplemental Investi ation 2006 Uplands A 6486-060512-256 05/11/02 0.0 - 1.0 HAI In-Place No Cap 6.47 Yes Yes Yes No Uplands A 6486-060512-257 05/11/02 1.0 - 2.0 HAI In-Place No Cap 9.34 Yes Yes Yes No Uplands A 6486-060512-258 05/11/02 2.0 - 3.0 HAI In-Place No Cap 7.26 Yes Yes Yes No Uplands B 6486-060512-259 05/11/02 0.0 - 1.0 HAI In-Place No Cap 13.8 Yes Yes Yes No Uplands B 6486-060512-260 05/11/02 1.0 - 2.0 HAI In-Place No Cap 15.4 Yes Yes Yes No Uplands B 6486-060512-261 05/11/02 2.0 - 3.0 HAI In-Place No Cap 5.42 Yes Yes Yes No Uplands C 6486-060512-262 05/11/02 0.0 - 1.0 HAI In-Place No Cap 4.86 Yes Yes Yes No Uplands C 6486-060512-263 05/11/02 1.0 - 2.0 HAI In-Place No Cap 44 Yes Yes Yes No Uplands C 6486-060512-264 05/11/02 2.0 - 3.0 HAI In-Place No Cap 7.99 Yes Yes Yes No ■ Uplands D 6486-060512-265 05/11/02 0.0 - 1.0 HAI In-Place No Cap 4.46 Yes Yes Yes No !1 Uplands D 6486-060512-266 05/11/02 1.0 - 2.0 HAI In-Place No Cap 30.2 Yes Yes Yes No Uplands D 6486-060512-267 05/11/02 2.0 - 3.0 HAI In-Place No Cap 7.01 Yes Yes Yes No Uplands E 6486-060515-369 05/14/02 0.0 - 1.0 HAI In-Place No Cap 10.2 Yes Yes Yes No Uplands E 6486-060515-370 05/14/02 1.0 - 2.0 HAI In-Place No Cap 4.22 Yes Yes Yes No Uplands F 6486-060515-376 05/14/02 0.0 - 1.0 HAI In-Place No Cap 5.55 Yes Yes Yes No Uplands F 6486-060515-377 05/14/02 1.0 - 2.0 HAI In-Place No Cap 8.64 Yes Yes Yes No Uplands F 6486-060515-378 05/14/02 2.0 - 3.0 HAI In-Place No Cap 11.2 Yes Yes Yes No Uplands G 6486-060515-373 05/14/02 0.0 - 1.0 HAI In-Place No Cap 7.86 Yes Yes Yes No Uplands G 6486-060515-374 05/14/02 1.0 - 2.0 HAI In-Place No Cap 22.8 Yes Yes Yes No Uplands G 6486-060515-375 05/14/02 2.0 - 3.0 HAI In-Place No Cap 9.64 Yes Yes Yes No Uplands H 6486-060515-357 05/14/02 0.0 - 1.0 HAI In-Place No Cap 32.8 Yes Yes Yes No Uplands H 6486-060515-358 05/14/02 1.0 - 2.0 HAI In-Place No Cap 11.2 Yes Yes Yes No Uplands H 6486-060515-358b 05/14/02 1.0 - 2.0 HAI In-Place No Cap 11 Yes Yes Yes No Uplands H 6486-060515-359 05/14/02 2.0 - 3.0 HAI In-Place No Cap 5.53 Yes Yes Yes No Uplands 1 6486-060515-363 05/14/02 0.0 - 1.0 HAI In-Place No Cap 6.7 Yes Yes Yes No Uplands 1 6486-060515-364 05/14/02 1.0 - 2.0 HAI In-Place No Cap 30.6 Yes Yes Yes No Uplands 1 6486-060515-365 05/14/02 2.0 - 3.0 HAI In-Place No Cap 6.31 Yes Yes Yes No Uplands I 6486-060515-365b 05/14/02 2.0 - 3.0 HAI In-Place No Cap 4.83 Yes Yes Yes No Uplands J 6486-060515-366 05/14/02 0.0 - 1.0 HAI In-Place No Cap 5.06 Yes Yes Yes No Uplands J 6486-060515-367 05/14/02 1.0 - 2.0 HAI In-Place No Cap 27.6 Yes Yes Yes No Uplands J 6486-060515-368 05/14/02 2.0 - 3.0 HAI In-Place No Cap 17.1 Yes Yes Yes No Uplands K 6486-060515-360 05/14/02 0.0 - 1.0 HAI In-Place No Cap 3.78 Yes Yes Yes No File No.4025-003-02 Table 1,July 11,2008 Page 5 of 9 GMENGINEER� Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA - Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Uplands K 6486-060515-361 05/14/02 1.0 - 2.0 HAI In-Place No Cap 17.2 Yes Yes Yes No Uplands K 6486-060515-362 05/14/02 2.0 - 3.0 HAI In-Place No Cap 6.36 Yes Yes Yes No Uplands L 6486-060511-253 05/10/02 0.0 - 1.0 HAI In-Place No Cap 11.9 Yes Yes Yes No Uplands L 6486-060511-253b 05/10/02 0.0 - 1.0 HAI In-Place No Cap 14.8 Yes Yes Yes No ■ Uplands L 6486-060511-254 05/10/02 1.0 - 2.0 HAI In-Place No Cap 4.64 Yes Yes Yes No 11 Uplands M 6486-060511-246 05/10/02 0.0 - 1.0 HAI In-Place No Cap 12.4 Yes Yes Yes No Uplands M 6486-060511-247 05/10/02 1.0 - 2.0 HAI In-Place No Cap 25.7 Yes Yes Yes No Uplands M 6486-060511-248 05/10/02 2.0 - 3.0 HAI In-Place No Cap 40.7 Yes Yes Yes No Uplands M 6486-060511-249 05/10/02 3.0 - 4.0 HAI In-Place No Cap 5.07 No Yes No No Uplands N 6486-060511-250 05/10/02 0.0.- 1.0 HAI In-Place No Cap 5.55 Yes Yes Yes No Uplands N 6486-060511-251 05/10/02 1.0 - 2.0 HAI In-Place No Cap 18.1 Yes Yes Yes No Uplands N 6486-060511-252 05/10/02 2.0 - 3.0 HAI In-Place No Cap 7.26 Yes Yes Yes No Uplands O 6486-060515-379 05/14/02 0.0 - 1.0 HAI In-Place No Cap 11.8 Yes Yes Yes No Uplands O 6486-060515-380 05/14/02 1.0 - 2.0 HAI In-Place No Cap 29.3 Yes Yes Yes No Uplands O 6486-060515-380b 05/14/02 1.0 - 2.0 HAI In-Place No Cap 14.1 Yes Yes Yes No Uplands O 6486-060515-381 05/14/02 2.0 - 3.0 HAI In-Place No Cap 7.32 Yes Yes Yes No Uplands P 6486-060515-384 05/14/02 2.0 - 3.0 HAI In-Place No Cap 6.93 Yes Yes Yes No Uplands Q 6486-060515-386 05/14/02 0.0 - 1.0 HAI In-Place No Cap 16.9 Yes Yes Yes No Uplands Q 6486-060515-387 05/14/02 1.0 - 2.0 HAI In-Place No Cap 23.3 Yes Yes Yes No Uplands Q 6486-060515-388 05/14/02 2.0 - 3.0 HAI In-Place No Cap 14.5 Yes Yes Yes No Restoration Area R 6486-060515-389 05/14/02 0.0 - 1.0 HAI In-Place No Cap 32.9 Yes Yes Yes Yes Restoration Area R 6486-060515-390 05/14/02 1.0 - 2.0 HAI In-Place No Cap 24.7 Yes Yes Yes Yes Restoration Area R 6486-060515-391 05/14/02 2.0 - 3.0 HAI In-Place No Cap 56.4 Yes Yes Yes No Restoration Area S 6486-060515-282 05/14/02 0.0 - 1.0 HAI In-Place No Cap 96.2 Yes Yes Yes Yes Restoration Area S 6486-060515-283 05/14/02 1.0 - 2.0 HAI In-Place No Cap 41.3 Yes Yes Yes Yes Restoration Area S 6486-060515-284 05/14/02 2.0 - 3.0 HAI In-Place No Cap 13.3 Yes Yes Yes No Restoration Area T 6486-060515-279 05/14/02 1.0 - 2.0 HAI In-Place No Cap 15.9 Yes Yes Yes Yes ■ Restoration Area T 6486-060515-280 05/14/02 2.0 - 3.0 HAI In-Place No Cap 16.1 Yes Yes Yes No 11 Restoration Area T 6486-060515-281 05/14/02 3.0 - 4.0 HAI In-Place No Cap 24.6 No Yes No No Restoration Area U 6486-060515-285 05/14/02 0.0 - 1.0 HAI In-Place No Cap 32.1 Yes Yes Yes Yes Restoration Area U 6486-060515-286 05/14/02 1.0 - 2.0 HAI In-Place No Cap 29.2 Yes Yes Yes Yes Restoration Area U 6486-060515-287 05/14/02 2.0 - 3.0 HAI In-Place No Cap 11.7 Yes Yes Yes No Restoration Area V 6486-060515-300 05/14/02 0.0 - 1.0 HAI In-Place No Cap 21.5 Yes Yes Yes Yes Restoration Area V 6486-060515-301 05/14/02 1.0 - 2.0 HAI In-Place No Cap 25.7 Yes Yes Yes Yes Restoration Area V 6486-060515-302 05/14/02 2.0 - 3.0 HAI In-Place No Cap 7.87 Yes Yes Yes No Restoration Area W 6486-060515-297 05/14/02 0.0 - 1.0 HAI In-Place No Cap 113 Yes Yes Yes Yes Restoration Area W 6486-060515-298 05/14/02 1.0 - 2.0 HAI In-Place No Cap 12.5 Yes Yes Yes Yes Restoration Area W 6486-060515-299 05/14/02 2.0 - 3.0 HAI In-Place No Cap 8.93 Yes Yes Yes No Restoration Area X 6486-060515-294 05/14/02 0.0 - 1.0 HAI In-Place No Cap 9.04 Yes Yes Yes Yes Restoration Area X 6486-060515-295 05/14/02 1.0 - 2.0 HAI In-Place No Cap 10.9 Yes Yes Yes Yes Restoration Area X 6486-060515-296 05/14/02 2.0 - 3.0 HAI In-Place No Cap 29.8 Yes Yes Yes No Restoration Area Y 6486-060515-291 05/14/02 0.0 - 1.0 HAI In-Place No Cap 17.9 Yes Yes Yes Yes Restoration Area Y 6486-060515-292 05/14/02 1.0 - 2.0 HAI In-Place No Cap 10.6 Yes Yes Yes Yes Restoration Area Y 6486-060515-293 05/14/02 2.0 - 3.0 HAI In-Place No Cap 101 Yes Yes Yes No Uplands Z 6486-060515-303 05/14/02 0.0 - 1.0 HAI In-Place Ca - Paved 9.33 No Yes No No Uplands Z 6486-060515-304 05/14/02 1.0 - 2.0 HAI In-Place Ca - Paved 23.2 No Yes No No Uplands Z 6486-060515-305 05/14/02 2.0 - 3.0 HAI In-Place Ca - Paved 5.34 No Yes No No Uplands Aa 6486-060515-272 05/14/02 0.0 - 1.0 HAI In-Place Ca (Propos 13.5 No Yes No No Uplands Aa 6486-060515-273 05/14/02 1.0 - 2.0 HAI In-Place Ca Pro osed 17.5 No Yes No No !!! Uplands Aa 6486-060515-274 05/14/02 2.0 - 3.0 HAI In-Place Ca (Proposed) 6.89 No Yes No No File No.4025-003-02 Table 1,July 11,2008 Page 6 of 9 G M E N G I N E E R S Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Uplands Ab 6486-060515-276 05/14/02 0.0 - 1.0 HAI In-Place Ca - Paved 41.2 No Yes No No Uplands Ab 6486-060515-277 05/14/02 1.0 - 2.0 HAI In-Place Cap- Paved 13.5 No Yes No No Uplands Ab 6486-060515-278 05/14/02 2.0 - 3.0 HAI In-Place Ca - Paved 5.87 No Yes No No Uplands Ac 6486-060510-223 05/09/02 3.5 - 4.5 HAI In-Place Ca - Soil/Paved 32 No Yes No No Uplands Ac 6486-060511-235 05/10/02 4.5 - 5.5 HAI In-Place Ca - Soil/Paved 58.5 No Yes No No Uplands Ac 6486-060511-236 05/10/02 5.5 - 6.5 HAI In-Place Ca - Soil/Paved 19.1 No Yes No No Uplands Ac 6486-060511-237 05/10/02 6.5 - 7.5 HAI In-Place Ca - Soil/Paved 26.8 No Yes No No Restoration Area Ad 6486-060515-288 05/14/02 0.0 - 1.0 HAI In-Place No Cap 2.75 Yes Yes Yes Yes Restoration Area Ad 6486-060515-289 05/14/02 1.0 - 2.0 HAI In-Place No Cap 5.05 Yes Yes Yes Yes Uplands Ae 6486-060515-268 05/14/02 0.0 - 1.0 HAI In-Place Ca - Paved 8.75 No Yes No No Uplands Ae 6486-060515-269 05/14/02 1.0 - 2.0 HAI In-Place Ca - Paved 14.5 No Yes No No Uplands Ae 6486-060515-270 05/14/02 2.0 - 3.0 HAI In-Place Ca - Paved 3.68 No Yes No No Uplands Af 6486-060510-216 05/09/02 0.0 - 1.0 HAI In-Place Ca - Paved 5.16 No Yes No No Uplands Af 6486-060510-217 05/09/02 1.0 - 2.0 HAI In-Place Ca - Paved 47.6 No Yes No No Uplands Af 6486-060510-218 05/09/02 2.0 - 3.0 HAI In-Place Ca - Paved 17.7 No Yes No No Uplands Af 6486-060510-219 05/09/02 3.0 - 4.0 HAI In-Place Ca - Paved 12.1 No Yes No No Uplands Ag 6486-060510-215 05/09/02 3.5 - 4.5 HAI In-Place Ca - SoiVPaved 4.96 No Yes No No Uplands Ag 6486-060510-215b 05/09/02 3.5 - 4.5 HAI In-Place Ca -Soil/Paved 5.43 No Yes No No Uplands Ah 6486-060510-208 05/09/02 0.5 - 1.5 HAI In-Place Sample of Cap 4.82 No No No No Uplands Ah 6486-060510-209 05/09/02 1.5 - 2.5 HAI In-Place Ca -Soil <2 ft 6.03 Yes Yes Yes No Uplands Ah 6486-060510-210 05/09/02 2.5 - 3.5 HAI In-Place Ca - Soil <2 ft 6.39 Yes Yes Yes No Uplands Ah 6486-060510-211 05/09/02 3.5 - 4.5 HAI In-Place Ca -Soil <2 ft 6.07 No Yes No No Uplands Ai 6486-060510-207 05/09/02 3.0 - 4.0 HAI In-Place Ca - Soil 9.37 No Yes No No Uplands A' 6486-060510-201 05/09/02 0.5 - 1.5 HAI In-Place No Cap 5.5 Yes Yes Yes No Uplands A' 6486-060510-202 05/09/02 1.5 - 2.5 HAI In-Place No Cap 7.12 Yes Yes Yes No Uplands A' 6486-060510-203 05/09/02 2.5 - 3.5 HAI In-Place No Cap 4.96 Yes Yes Yes No Uplands Ak 6486-060510-200 05/09/02 0.0 - 1.0 HAI In-Place No Cap 4.93 Yes Yes Yes No Uplands Ak 6486-060515-392 05/14/02 0.0 - 1.0 HAI In-Place No Cap 3.6 Yes Yes Yes No Uplands Ak 6486-060515-393 05/14/02 1.0 - 2.0 HAI In-Place No Cap 3.98 Yes Yes Yes No Uplands Al 6486-060510-224 05/09/02 0.5 - 1.5 HAI In-Place Ca (Proposed) 6.72 No Yes No No Uplands Al 6486-060510-225 05/09/02 1.5 - 2.5 HAI In-Place Cap (ProposeLdL(Proposed7.93 No Yes No No uplands Al 6486-060510-226 05/09/02 2.5 - 3.5 HAI In-Place Cap (ProposeLdL(Proposed7.63 No Yes No No Uplands Al 6486-060510-227 05/09/02 3.5 - 4.5 HAI In-Place Ca (Proposed) 3.85 No Yes No No Uplands Am 6486-060511-228 05/10/02 0.0 - 1.0 HAI In-Place Ca (Proposed) 9.36 No Yes No No Uplands Am 6486-060511-229 05/10/02 1.0 - 2.0 HAI In-Place Ca (Proposed) 12.5 No Yes No No Uplands Am 6486-060511-230 05/10/02 2.0 - 3.0 HAI In-Place Ca (Proposed) 9.9 No Yes No No Uplands Am 6486-060511-231 05/10/02 3.0 - 4.0 HAI In-Place Ca (Proposed) 5.55 No Yes No No Uplands Ao 6486-060515-353 05/14/02 0.0 - 1.0 HAI In-Place Ca (Proposed) 14 No Yes No No Uplands Ao 6486-060515-354 05/14/02 1.0 - 2.0 HAI In-Place Ca (Proposed) 25.5 No Yes No No Uplands Ao 6486-060515-355 05/14/02 2.0 - 3.0 HAI In-Place Ca (Proposed 10.1 No Yes No No Uplands Ao 6486-060515-356 05/14/02 3.0 - 4.0 HAI In-Place Ca (Proposed) 7.64 No Yes No No Uplands An 6486-060511-232 05/10/02 0.5 - 1.5 HAI In-Place Ca (Proposed) 54.3 No Yes No No Uplands An 6486-060511-233 05/10/02 1.5 - 2.5 HAI In-Place Ca (Proposed) 17.6 No Yes No No Uplands An 6486-060511-234 05/10/02 2.5 - 3.5 HAI In-Place Ca (Proposed) 5.61 No Yes No No Uplands Ap 6486-060515-350 05/14/02 0.0 - 1.0 HAI In-Place Ca (Proposed) 5.81 No Yes No No Uplands Ap 6486-060515-351 05/14/02 1.0 - 2.0 HAI In-Place Cap (ProposeLdL(Proposed9.43 No Yes No No Uplands Ap 6486-060515-352 05/14/02 2.0 - 3.0 HAI In-Place Ca (Proposed) 5.84 No Yes No No Uplands Ag 6486-060511-238 05/10/02 0.0 - 1.0 HAI In-Place No Cap 4.25 Yes Yes Yes No Uplands Ag 6486-060511-238b 05/10/02 0.0 - 1.0 HAI In-Place No Cap 4.81 Yes Yes Yes No Upland Ag 6486-060511-239 05/10/02 1.0 - 2.0 HAI In-Place No Cap F 5.79 Yes Yes Yes No File No. 4025-003-02 Table 1,July 11,2008 Page 7 of 9 GMENGINEERS Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Uplands Ar 1 6486-060511-242 05/10/02 0.0 - 1.0 HAI In-Place No Cap 3.7 Yes Yes Yes No Uplands Ar 1 6486-060511-243 05/10/02 1.0 - 2.0 HAI In-Place No Cap 4.8 Yes Yes Yes No Additional Testing for Risk Assessment 2007-2008 Restoration Area HA-1 HA-1 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 19 No No No No ■ Restoration Area HA-1 HA-1 2-3 04/23/07 2.0 - 3.0 GEI In-Place No Cap 20.4 Yes Yes Yes No /1 Restoration Area HA-2 HA-2 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 5.71 No No No No Restoration Area HA-2 HA-2 2-3 04/23/07 2.0 - 3.0 GEI Removed No Cap 9.28 No No No No Restoration Area HA-3 HA-3 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 10.3 No No No No Restoration Area HA-3 HA-3 2-3 04/23/07 2.0 - 3.0 GEI Removed No Cap 6.11 No No No No Restoration Area HA-4 HA-4 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 3.94 No No No No Restoration Area HA-4 HA-4 2-3 04/23/07 2.0 - 3.0 GEI In-Place No Cap 6.16 Yes Yes Yes No Restoration Area HA-5 HA-5 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 8.28 No No No No Restoration Area HA-5 HA-5 2-3 04/23/07 2.0 - 3.0 GEI In-Place No Cap 12.4 Yes Yes Yes No Restoration Area HA-6 HA-6 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 7.22 No No No No Restoration Area HA-6 HA-6j2-3 04/23/07 2.0 - 3.0 GEI In-Place No Cap 17.4 Yes Yes Yes No Restoration Area HA-7 HA-7 0-1 04/23/07 0.0 - 1.0 GEI Removed No Cap 6.5 No No No No Restoration Area HA-7 HA-7 2-3 04/23/07 2.0 - 3.0 GEI In-Place No Cap 5.09 Yes Yes Yes No Uplands HA-8 HA-8 0-1 04/23/07 0.0 - 1.0 GEI In-Place No Cap 5.19 Yes Yes Yes No Uplands HA-8 HA-8 2-3 04/23/07 2.0 - 3.0 GEI In-Place No Cap 5.16 Yes Yes Yes No Restoration Area SP-1 SP-1 3 06/21/07 2.5 - 3.5 GEI Removed No Cap 21.1 No No No No Restoration Area SP-1 SP-1 5 06/21/07 4.5 - 5.5 GEI In-Place No Cap 4.59 No Yes No No Restoration Area SP-2 SP-2 2 06/21/07 1.5 - 2.5 GEI In-Place No Cap 8.56 Yes Yes Yes Yes Restoration Area SP-2 SP-2 4 06/21/07 3.5 - 4.5 GEI In-Place No Cap 7.96 No Yes No No Uplands SP-3 SP-3 3 06/21/07 2.5 - 3.5 GEI In-Place No Cap 2.74 Yes Yes Yes No Uplands SP-3 SP-3 5 06/21/07 4.5 - 5.5 GEI In-Place No Cap 2.88 No Yes No No Restoration Area SP-4 SP-4 4.5 06/21/07 4.0 - 5.0 GEI In-Place No Cap 8.49 No Yes No No Restoration Area SP-4 SP-4 6.5 06/21/07 6.0 - 7.0 GEI In-Place No Cap 8.24 No Yes No No Restoration Area SP-5 SP-5 3 06/21/07 2.5 - 3.5 GEI In-Place No Cap 4.06 Yes Yes Yes No Restoration Area SP-5 SP-5 5 06/21/07 4.5 - 5.5 GEI In-Place No Cap 2.43 No Yes No No Restoration Area SP-6 SP-6 3 06/21/07 2.5 - 3.5 GEI Removed No Cap 16 No No No No Restoration Area SP-6 SP-6 5 06/21/07 4.5 - 5.5 GEI In-Place No Cap 6.23 No Yes No No Restoration Area SP-7 SP-7 5 06/21/07 4.5 - 5.5 GEI In-Place No Cap 1.89 No Yes No No Restoration Area SP-7 SP-7 7 06/21/07 6.5 - 7.5 GEI In-Place No Cap 3.33 No Yes No No Restoration Area SP-8 SP-8 2 06/21/07 1.5 - 2.5 GEI In-Place No Cap 6.52 Yes Yes Yes Yes Restoration Area SP-8 SP-8 4 06/21/07 3.5 - 4.5 GEI In-Place No Cap 6.94 No Yes No No Restoration Area SP-9 SP-9 06/21/07 0.0 - 1.0 GEI In-Place No Cap 12.2 Yes Yes Yes Yes Uplands HA-10 HA-10 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 5.2 Yes Yes Yes No ■ Uplands HA-11 HA-11 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 3.8 Yes Yes Yes No !( Uplands HA-12 HA-12 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 4.7 Yes Yes Yes No Uplands HA-13 HA-13 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 5.4 Yes Yes Yes No Uplands HA-14 HA-14 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 5.4 Yes Yes Yes No Uplands HA-15 HA-15 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 13 Yes Yes Yes No Uplands HA-16 HA-16 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 9.9 Yes Yes Yes No Restoration Area HA-17 HA-17 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 32 Yes Yes Yes Yes Restoration Area HA-18 HA-18 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 32 Yes Yes Yes Yes Pond HA-19 HA-19 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 110 No Yes No Yes Restoration Area HA-20 HA-20 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 16 Yes Yes Yes Yes Pond HA-21 HA-21 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 12 No Yes No Yes Pond HA-22 HA-22 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 17 No Yes No Yes Restoration Area HA-23 HA-23 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 10 Yes Yes Yes Yes File No.4025-003-02 Table 1,July 11,2008 Page 8 of 9 GMENGINEERS Sample Inclusion in Risk Assessment Data Sets Depth at Time of Capping Status Total Arsenic HHRA- Librarian, HHRA- Sample Sample Sampling Sampled of In-Place (EPA 6010) Maintenance Worker, Excavation ERA- ERA- Area Location Sample Designation Date (feet bgs) By Soil Disposition Samples (mg/kg) Library/Park User Worker Terrestrial Aquatic Restoration Area HA-24 HA-24 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 6.9 Yes Yes Yes Yes Restoration Area HA-25 HA-25 0-1 FT 05/07/08 0 - 1 GEI In-Place No Cap 25 Yes Yes Yes Yes Restoration Area HA-26 HA-26 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 16 Yes Yes Yes Yes Restoration Area HA-27 HA-27 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 12 Yes Yes Yes Yes Restoration Area HA-28 HA-28 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 2.8 U Yes Yes Yes Yes Restoration Area HA-29 HA-29 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 3.2 U Yes Yes Yes Yes Restoration Area HA-30 HA-30 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 4.5 Yes Yes Yes Yes Restoration Area COMP-1 COMP-1 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 7.2 Yes Yes Yes Yes Restoration Area COMP-2 I COMP-2 0-.5 FT 05/07/08 0 - 0.5 GEI In-Place No Cap 1.3 U Yes Yes Yes Yes Notes: bgs=below ground surface mg/kg=milligrams per kilogram EPA=US Environmental Protection Agency HHRA=Human Health Risk Assessment ERA=Ecological Risk Assessment HAI=Hahn Associates, Inc. Apex=Apex Environmental Consulting GEI=GeoEngineers, Inc. 'This sample is a composite of two samples that were analyzed individually for Arsenic. In order not to duplicate data,we did not include the composite sample results in the risk assessment. 2The disposition of the soil represented by this sample is ambiguous based on information provided by HAI. In order to be conservative,we have assumed that it remains in-place. 3The sample depth is not known based on information provided by HAI. In order to be conservative,we have assumed that the sample was taken from surface soil at one foot bgs. Cap(Proposed) indicates the sample will be under a mulch cap in the pine tree area or central tree area. Port: 4\4025003\02\Finals\402500302Tables.xls File No.4025-003-02 Table 1,July 11,2008 Page 9 of 9 GMENGINEER� r TABLE 2 POND DISCHARGE ANALYTICAL RESULTS TIGARD LIBRARY to 13500 SW HALL BOULEVARD TIGARD, OREGON wo Total Arsenic Total Suspendedo i s Turbidity M (EPA Method 6020) (EPA Method 160.2) 2130B) Sample Designation Date (,ug/I) (mg/1) (NTU) Pond Discharge-1 02/02/08 1.12 8.00 15 Pond Dischar e-2 03/14/08 1.21 73.0 52 Notes: Ng/I=micrograms per liter mg/I=milligrams per liter SM=Standard method go NTU =nephelometric turbidity units EPA= U.S. Environmental Protection Agency Port: 4\4025003\02\Finals\402500302Tables.xl s rrr it wa AN to to �1 File No.4025-003-02 Table 2,July 11,2008 GMENGINEER� rr 10 TABLE 3 SUMMARY OF SOIL ANALYTICAL DATA BY DEPTH' TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON Mean Median Sample Number of Samples Minimum Maximum (Detections (Detections Depth Number of Number of Exceeding Background Detected Detected Only) Only) (ft bgs) Samples Detections (7 mg/kg)3 (mg/kg) (mg/kg) (mg/kg) (mg/kg) 0 to<1 120 100 37 1.98 113 11.4 4.86 1 to<2 53 47 28 2.65 44 13.5 8.56 2 to<3 37 35 21 2.74 101 14.3 7.29 3 to<4 5 5 2 5.07 24.6 10.1 6.94 >_4 8 8 2 1.89 8.49 4.76 3.96 irr Notes: 'Sample depths categorized by the top of the sample depth interval,where applicable. 2Samples included are: 1)those that represent soil left in-place with no existing or proposed pavement,soil or mulch cap, and 2)those that represent soil left in-place with a soil cap less than 2 feet thick. 3Background value(7 mg/kg)is the default background concentration issued in DEQ's Memorandum from Toxicology Workgroup,October 28,2002. ft bgs=feet below ground surface +Ire mg/kg=milligrams per kilogram Port: 4\4025003\02\Finals\402500302Tables.xls +rr irr rw rw File No.4025-003-02 Table 3,July 11,2008 GEOENGINEER� ire TABLE 4 HUMAN HEALTH RISK-BASED SCREENING ARSENIC IN SOIL TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON MRL Detected Compounds Minimum Maximum Minimum Maximum Maximum Sample Detection 90%UCL2 Data Sets mg/kg mg/kg mg/kg mg/kg ID Frequency mg/kg Librarian, Maintenance Worker,Adult and Child Park User Surface Soil 0-3 feet b s ' 1.3 1 3.2 1.98 1 113 1 6486-060515-297 1 179/207 1 71.9 Applicable Site-Specific Risk-Based Concentrations3 Librarian 8,3 Maintenance Worker 11 Adult and Child Park User 2.6 Excavation Worker All Soil' 1.3 3.2 1.7 264 12S(Dup) 284/324 12.9 Applicable DEG Generic Risk-Based Concentrations3 Excavation Worker 370 DEQ Back round Concentration Arsenic 7 Notes: 'See section titled"Human Health Data Sets"for a specific description of the samples used in the risk calculations. 290%UCL was calculated using EPA's ProUCL software(version 4.00.02). The method used to calculate the 90%UCL is the one that ProUCL recommended for calculating the 95%UCL. 3See section titled"HHRA Results"for a discussion of how risk-based concentrations were calculated. 4Background value referenced is the default background concentration issued in DEQ's Memorandum from Toxicology Workgroup,October 28,2002. Shading indicates that the 90%UCL exceeds a site-specific or DEQ generic risk-based concentration. bgs=below ground surface UCL=Upper Confidence Level mg/kg=milligrams per kilogram MRL=Laboratory Method Reporting Limit Port: 4\4025003\02\Finals\402500302Tabl es.xl s File No.4025-003-02 G EO E N G I N E E R Table 4,July 11,2008 « r - « i' e ✓ ..✓ ) . .; �. 4% t r _ "4{ r � • `. � �y �"� t yet '� . � � I « r, t 0 •.�" a � "'"- •tom •��.,� � I i � ... 1 «•• �. r, T • • "•• ';r` • '�. y,.. .=w iIr te Al / • c �� « •Y' � y r- zsa � y : L i• . 4r9►`:" • � •�" I .� r-� ,Y* ''.fir - t44��J,,�,, ' • t •� .12 f-/J� i y f � � �. • �„",�""R � � a'yf� _` �� j «kit Otl�+t ,� fi A i K7 Y +� car Pal ' NATIONAL �ES,000 o I 3000 aoap /17- GEOGRAPHIC , 5 0 KtLOWTERS It�Q _. MITEAS 05/17/07 Vicinity Map ' Tigard Library Tigard. Oregon GWENGINEERS r Figure 1 1 111111111ONS 1111111MOM 1111111000M 10100 smona VOINEM! PENN posma gnome 90=mm nomome MINEENEO P:\4\4025003\02\CAD\FinalRI\Figure2.dwg MSY:MWJ 07/08/08 N W E S1 C) S30 S O 52:"� 70 0 70\ \Saa,\ ®A Feet S50 ♦. B Ar 0_51.lb ♦, �D S O SES14�'14* g He S160\ ♦ H.ar,dred yea�03 S70, 004 a �- flood plaioK O % O Ok 097 {7 boundary ® SS-2 E 8\� O ® ♦ii�n I 001 ' M SS-35 36 F ; O SS-33 SS-34 ® N O V gj G SS-30 SS-31 O O (D e 1 O 0 1505 i SS-32 i O ) SS-29 1 I -24 13S S -25 p 26 SSS-27 SSS-28 f O , I SOS-21 ss-t0 ` lit0005 006 / 007 '0j8 1, j I I S _ 0 1 O 17S 20 S j 7 SS-15 SS-16 -S 7 SS-18 SS-19 20 i 0 0 0 0 S0S , 1 b S SS-9 SS8-66 10 Q l_ 026 Ap 18S2 s pOpp io SS-7 1 0 pppp ?P o O 1° I/ , j o 27S o , o SS-59 Ss 6 SS-61 62 63 Q SSOS 19S 23S EB I i 0 ' Stormwater r 28S Al o (DIII' il' ♦ Swale „ 9s 8s s 2 O 24S OSS-55 O SS-56 SS-57 SS-58 z ss-5a o o ° % R HA-18(0-1) ♦, t / t I ! 3S V O SS 52 9 SS-50 O \ SS-4? SS-48 SS-49 - SS_Sb I HAW0-0.5) II P (0-1 HA-16 5. HXfo(0-0.5) HA ( ) / j Z #',f' ,, \ 2S ®S -17 0-1 S/ i / / Pond W I � o ®\ , ,. _ .- Y Discharge to V ' " , os' ® HA-sc Fanno Creek 1��i ) HA-9A- A� 4Sss 42 sa AcS as , � T A-21 (0-0.5) o O O _ HA_12(0-1j a Stfln ----®Ah J`\ _ H (0-0,5) x ED 11-3 � SS-38 EXtenHA-9B a �A 11 0-1 0 Street T" S-411 SP-8 +' 6s A `Wa\t SS-39 -� J " -29 0.5) � �A� dSo ® O "'�- .- - Q C\„ ,,,,• 5(0-1) l 7 •.(0-0.5) �. . - T '. 915= _ . . 0h d HA-2 ( ® Ag e Af - "% '" `�` = S1S` HA-27(0-0.5) k 004* HA-10(0-1) - r = -, = 7 HA-5 A 28(0-0.5) - _ ,. - OMP-2(0-0.5) ads - HA-7 3 3 COMP-1 (0 .5) 00 HA 8 t i - 90 Outfall Legend: I HA-1 -HA-30 Hand-auger sample locations ' (April 2007 and May 2008) SP-1 0 Soil sample locations (June 2007) r oEOO Pre-2006 Soil samples ® Arsenic Contaminated Fill Area Site Layout (Placed During Summer 2007 Hall/Wall Improvements) Nates: Tigard Library 1.The locations of all features shown are approximate. Tigard, Oregon 2.This drawing is for information purposes.It is intended to assist in showing features discussed in an attached document.GeoEngineers,Inc.can not guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers,Inc.and will serve as the official record of this communication. GEOENGI NEERFigure 2 Reference:Base Drawing dated 10/2006,provided by Hahn and Associates. P. 01 Noma ONE" /NOW 1/MOM" pow" /�■1! �� �� r�-7 �"-- 7 t P:\4\4025003\02\CAD\FinalRI\Figure3.dwg MSY:MWJ 07/08/08 N W E s1 o 33e S °S2 _ 70 0 70 � ------ \sae (DA Feet ., 44, Ar f \ 550-$_1, ���„• _ 5 '�._, �j+14 0q�p•„••iyii•�•�•un.na• Aq 006' g3 H® l \ •. Sts e \ C 5190\ ® G ---Hundred vecr S70` ` 004 y flood poinl< 03 \ ; p 007” C3 boundury ® E L ED •2. ! 1 , SS-35 -36 F SS-33 SS-34 N O ® G I ' SSS-30 SS-31 O O i I I I SS-32 10 i �\ 0 1 SS-29 SS-26 O-24 135 1 SS-21 �p p a -25 O O O 1 . L O SS-O p005 / 006 6 007 ff 17S ° k 21S ss 15 O SS 16 S 7 SS-18 SS-19 SS-20 p D p p p 1 S -g Sb-66 10 UI'j. 'WI, 1 W 026P � 5110 V os �OOp SSS-7 0 I OOOp I� t , f ° 27S o 0 1 Q o SS-59 SS-6 SS-61 62 3 � ��nl�l) . O A rl SS-5 19S -lis71!1 I ' 4 p o z s Ai l!Nu I ' :� Stormwater o n l n i • Swale m! 9S 8S $ 2 Ilj •� `. 24S pSS-55 O pSS-56 SS-57 SS-58 t ,9 ss-54 0 0 ° l� l!\^ R� HA-118(0-1) t � V I 3S i i 55p47 5-48 0 SSS 49 SS-50 SS-5b SS-52 i ,n HA-16 5- . HAt9(0-0.5) HALO(0-0.5) / � Q 5 3/ o S / / / f Z� `�, 325* � HA-1 i(0-1) ��v xo / / ® \ - Y Pond Discharge to 30S' HA-9A HA-9C :Fanno Creek is }� Al o 0 42 �;so '��4 -� ” -- l�� s s T A-21 (0-0.5) l HA-13(0-1) � � � -22(0-0.5)�•, Aa —(DAbT / tl HA-26(0-0.5) X , I SS-3F - t oIA-11 (0-1) S�CeSS �4:- P$ s WaHA 29(0 7S Ae SS-39 -0.5) Ad _ - �.• ••�• HA-2�5,•(0•-•1')o 14s •.HA-23 ®A A` s ••• HA-27(0-0.5)i �'•� '•., 004* HA-10(0-1) — HAS - c> - --i J HA 5 . i P A, SP 6 t, 3, _ HA-28(0-0.5) S HA-6 COMP-2(0-0.5) SP-9 .• o A ,A YaA . �a; HA-3 Sp=3 ob6 / ♦, HA-2;'/ COMP-1 (0 .5) HA4* 00 ��`✓... of .90 ' Legend: Outfall HA-1 - HA-30 Hand-auger sample locations (April 2007 and May 2008) - SP.1 () Soil sample locations (June 2007) +� 000 Pre-2006 Soil samples Arsenic Contaminated Fill Area Current and Historic Soil (Placed During Summer Hall/Wall Sample Locations Improvements) Notes: Tigard Library 1.The locations of all features shown are approximate. Tigard, Oregon 2.This drawing is for information purposes.It is intended to assist in showing features discussed in an attached document.GeoEngineers, Inc.can not guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc.and will serve as the official record of this communication. GEOENGINEERS Figure 3 Reference:Base Drawing dated 10/2006,provided by Hahn and Associates. i 0 0 o o� o O C= O nl HA-17;`(0-1) Concentration 05/07/08 32 III HA-18'(0 1 ? Concentration m k HA-18 (111.5-2-5Concentration m /k T 05 07 OS 32 115/07/089.9 0* y� HA-15 (15. -2.5 > Concentration (mg/kg) �i 05 07 08 13 HA 1S 0-C.S Concentration (m /k ) 05 07 08 110 I HA-14 0 1 : f Concentrotion (mg/kg) 05/07/08 1 5.4 .HA-13; 0 Concentration (mg/kg) rero�.�.ro�# Concentration(µg/ll II 05/07/08 5.4 02 02 08 1.12 ' HConcentration m k raw wawa.-*. Concentration cµg/1) 0 05/07/08 1 4.7 A-11 f0'-1 Concentration m /k D PON o3 is oa 1.2t 1 05/07/08 1 3.8 I 1 - .•••..•,•.'•••..'• z:; Concentration (m k HA-10 (01) Concentration (m /k ) •� HA0503;p 05 0707708 07 08 5.2 05 07 08 16 HA-21 0-0.5 Concentration m k to 05 07 08 12 �, HA 2 ..Q-Q,5) Concentration (mg/kg) 17 _� i■ 05/07/08 Y. Concentration m k g) WAL �1F.:' _ 05/07/08 10 1. i'�a 1' '' i HA- 25 0-1 Concentration (mgk EXTENSION .: ':. .. \ ta_,, ;. ". .•..•'..•"..•.�•..;,•. 05 07 08 25 COMP-2;{0-0.5 Concentration m /k ) I lr,'•'.a �� :HA'30'(0-0.5) ' Concentration (m /k Y. 05 07 08 <1.3 O5/07/08 .•�.•••O�.`\�', .�:•; HA-290-0.5 Concentration m k \ �'' V 5/0� NA-26 (0-0.5)40 Concentrotion •� �` �'. •'.' 05 07 08 16 Q ;-::•.; `` ,, HA-24 (0-0.5)I;;I: Concentration m k o I ` K 05 07 08 16.9 o D <. �•' COMP-1 0-{15;? Concentration (m /k ) 05/07/08 7.2 HA,'-27 0-0. Concentration (m k CD Q y'•• N. - �.' �� 05/07/08 1 12 HA'-28 (0-0.5) 1 Concenuation (mg/k 05/07/08 1 <2.8 � o a�_.�-..•. -" Legend: , M _ u}i I sss HA-10 0-1 Concentrotion (m k Hand Auger/Depth J I 05/07/08 5.2 Arsenic Concentration ' N a Q T: i W E Hall/WaCut l Impros(Cutvementepth )feet During ; S Lj U.N Arsenic Contaminated Fill Area 60 0 60 M R;N (Placed During Summer 2007 o Hall/Wall Improvements)Ln Feet N a Soil Exposed by 2007 Hall/Wall Improvement Activities Supplemental Investigation LL Pinebrook Stream/Wetland Area Sample Locations with Arsenic Data Notes: Tigard Library N1.The locations of all features shown are approximate. Ng/] Micrograms Per Liter Tigard, Oregon c%) 2.This drawing is for information purposes.It is intended to assist in showing features discussed o mg/kg Milligrams Per Kilogram CD in an attached document.GeoEngineers,Inc.can not guarantee the accuracy and content of electronic files. to N The master file is stored by GeoEngineers,Inc.and will serve as the official record of this communication. C]EOENGINEERS Figure 4 v Reference:Base map provided by The City of Tigard. a P:\4\4025003102\CAD\402500302F5.dwg AJR:MWJ 06/20/08 PRIMARY PRIMARY SECONDARY SECONDARY TERTIARY EXPOSURE HUMAN ECOLOGICAL SOURCES RELEASE SOURCES RELEASE SOURCE ROUTES RECEPTORS RECEPTORS MECHANISMS MECHANISMS a CU p Q o 0 o u O Historic Land Application Orchards of Arsenic— On—Site Soil/ Ingestion • • • • • • On & Off—Site Containing Sediment Pesticides Dermal Contact • • • • • • Off—Site Overland Soil Flow Particulate Emissions EXPLANATION: Ingestion Air • • • • • POTENTIALLY COMPLETE PATHWAY Dermal Contact Conceptual Site Model Tigard Library Notes: Tigard, Oregon 1.This drawing is for information purposes.It is intended to assist in showing features discussed in an attached document.GeoEngineers,Inc.can not guarantee the accuracy and content of electronic files.The master file is stored G EOE NG I N E E RS Figure 5 by GeoEngineers, Inc.and will serve as the official record of this communication. FIGURE 6 BOX PLOT OF ARSENIC CONCENTRATIONS IN SOIL BY DEPTH TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON 120 110 _ Maximum 100 ♦Mean — 90 50th Percentile -{ — Minimum rn as 80 E � = 70 Notes: O Top and bottom of boxes i represent the 75th and 60 25th percentiles, d respectively. V C O 50 Sample depth is based on U V the top of the sample = depth interval,if i40 I T applicable. Q I Samples included in this 30 chart are those soil samples in which arsenic was detected that represent(1)soil left in- place with no existing or proposed cap,or(2)soil left in-place with a soil 10 � `" ..o less than 9 feet thick 0 to<1 1 to<2 2 to<3 3 to<4 >_4 Sample Depth(ft bgs) own P:\4\4025003\02\CAD\FinalRI\Figure7.dwg MSY:MWJ 07/08/08 N WE S10 Sia .S2 S 70 0 70 � sa ° Feet Ar ' S50 S110 t ® 516 OW Aq s I I I 47 0 002 001 0 SS-35 ' I SS-33 SSS-34 0 O O 30 S00-31 O 155 \ • I I SS-32 O O -24 il 05 _25 / SSS-27 SSS-28 SS-29 `�•. J 007 008 O 0 ��.•Fo \ ;7 SS-18 SSS-19 SOS 20 r.. I I ;f 10 I I �_I Ar 218 2S i 0 11 � 0 4 y O Ari 3 `l I SS-5 I l l il 3£ I I I II I Iml g5 p ''lilt 24S -56 g -. I2 Z�5 SS:ia 7 � � • Q .S I I •••i p I i V p • 55-47 SS-48 I I I I P 3 HA-19(0-0.5) •- r I HA-16(1,5 .5) HA-1f(0-1) Pond HA-9C I HApS' HA-9A q� 4SS52 SL �� ' - + I o 5a . ) HA-13(0-1) `� i "z a HA- -22(0-0.5 -12(0-1) � ,, •.. � 26(0-0.5) o 3 1 (0-1) o -as Wall gtreet Ex - _ $ hr.-29(0-0.5) 7S HA-98 �A-34 40a�r)� ( 6� Ae 39 23 --_- ss , � E@ Al rD AfSP 4 �t 1 n.dauulnununnaiu,r3 004' HA-70(0 1) HA-27 0 _ A _ .4 - — Sp a -SP n s-. �.� -, __ . HA 28(0 05) HA-6 HA-214}(0-0.5) Q P-2(0-0.5) SP-3 YHA-7 06` ` ••,, i W � , -2 COMP-1 (0 .5) HA-88 I j a I I - Legend: I � HA-1 -HA-30 * Hand—auger sample locations I OUaI' (April 2007 and May 2008) 77 $P-1 0 Soil sample locations (June 2007) 09. Pre-2006 Soil samples 8 I Locality of Facility l ' Approximate Area of Soil Exceeding ® Adult and Child Park User RBC (2.6 mg/kg) and Background (7 mg/kg) Areas Exceeding Screening Criteria Paved Cap Approximate Area of Soil Exceeding Tigard Library f4obs: Freshwater Sediment (6 mg/kg) and. Tigard, Oregon 'TM°"°°"°"°a•""�"�°"°""•°° °'"'" Sediment Bioaccumulation (7 mg/kg) SLVs z nae drawing k for edomagm pFsposes.n fa hbnd.d b seat In efn ft feaeaes d ommW In en afednd de www GwErghmm I=w nd guxantn fro so...y end cmtW ofeMe ftr c flea. .0 RkkUa.fwedby ...InGandwfl..Veeeff.efld.lecaaor GEOENGINEERS� Figure 7 9.RBC-Risk Baso Cawentifm 4.SLV=Oregon Depedmwd of Eovkonmenfel gaelfy Level f SpeeNiq Level Vale. Reference:Baso Dmwlq deled MM,provided by Helm and Asaadslse. GEOENGINEERS APPENDIX A LABORATORY ANALYTICAL DATA r 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax err �n Wednesday, March 26,2008 Chris Breemer GeoEngineers 15055 SW Sequoia Pkwy,# 140 Portland, OR 97224 +�+ RE:Tigard Library/4025-003-02 �r Enclosed are the results of analyses for samples received by the laboratory on 3/14/2008 at10:10:00AM. Thank you for using Apex Labs. We appreciate your business and strive to provide the highest quality services to the environmental industry. rir It you have any questions concerning this report or the services we offer, please feel free to contact me uy email at: dthomas(c)apex-labs.com, or by phone at 503-718-2323. trr im rir wrr rr Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of /, �� custody document.This analytical report must be reproduced in its entirety. i� Darwin Thomas,Sales/Marketing Page 1 of rr rrrl Apex Labs 12232 S.W.Garden Place Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 ANALYTICAL REPORT FOR SAMPLES SAMPLE INFORMATION Vll Sample ID Laboratory ID D9atrix Date Sampled Date Received Pond Discharge-2 A803138-01 Water 03/14/08 08:10 03/14/08 10:10 1 1N a 11116 lla tri No W Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. V Darwin Thomas,Sales/Marketing Page 2 of 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 ANALYTICAL SAMPLE RESULTS Total Metals by EPA 6020(ICPMS) Reporting Analyte Result MDL Limit Units Dilution Date Analyzed Method Notes Pond Discharge-2 (A803138-01) Matrix: Water Arsenic 0.00121 --- 0.00100 mg/L 1 03/17/08 18:00 EPA 6020 rw WIII nlrf >r111 4r11 Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. if Darwin Thomas,Sales/Marketing Page 3 of M 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 ANALYTICAL SAMPLE RESULTS Conventional Chemistry Parameters Reporting Analyte Result MDL Limit Units Dilution Date Analyzed Method Notes Pond Discharge-2 (A803138-01) Matrix: Water ) Total Suspended Solids 73.0 --- 5.00 mg/L 1 03/14/08 18:34 EPA 160.2 Yf Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 4 of 9 ow 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 VIII QUALITY CONTROL(QC)SAMPLE RESULTS dw Total Metals by EPA 6020(ICPMS) Reporting Spike Source %REC RPD Analyte Result MDL Limit Units Dil. Amount Result %REC Limits RPD Limit Notes r Batch 8030150-EPA 3015 Water Blank(8030150-BLKl) Analyzed:03/17/08 13:25 EPA 6020 — tilll Arsenic ND --- 0.00100 ing/L I --- --- -- --- --- --- LCS(8030150-BS1) Analyzed:03/17/08 13:28 EPA 6020 — — --- — +�It Arsenic 0.114 --- 0.00100 mg/L 1 0.111 103 80-120% r� r� 1Y011 qIr i111 lil Y11 lillll Iri Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 5 of 9 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 ProjectNumber: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 QUALITY CONTROL(QC)SAMPLE RESULTS Conventional Chemistry Parameters I Reporting Spike Source %REC RPD Analyte Result MDL Limit Units Dil. Amount Result %REC Limits RPD Limit Notes Batch 8030142-Total Suspended Solids Water Blank(8030142-BLKl) Analyzed:03/14/0818:34 EPA 160.2 Total Suspended Solids ND --- 5.00 mg/L 1 --- --- --- --- --- --- Reference(8030142-SRMl) Analyzed:03/14/08 18:34 EPA 160.2 Total Suspended Solids 98.0 --- mg/L 1 98.6 99 90-110% IIIA 111111 ( Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 6 of 9 +�r Apex p 12232 S.W.Garden Place yr Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 trn SAMPLE PREPARATION INFORMATION Apex Laboratories (--- Total Metals by EPA 6020(ICPMS) Sample Default RL Prep Lab Number Matrix Method Sampled Prepared Initial/Final Initial/Final Factor EPA 3015 Batch: 8030150 A803138-01 Water EPA 6020 03/14/08 08:10 03/14/08 14:45 45mL/50mL 45mL/50mL 1.00 Conventional Chemistry Parameters Sample Default RL Prep Lab Number Matrix Method Sampled Prepared Initial/Final Initial/Final Factor Total Suspended Solids i Batch: 8030142 A803138-01 Water EPA 160.2 03/14/08 08:10 03/14/08 11:38 100mL/1N/A 100mL/1mL NA nr i� +rN rr Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 7 of 9 rrt Apex Labs 12232 S.W.Garden Place Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,9 140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 Notes and Definitions Qualifiers: ■i Notes and Conventions: DET Analyte DETECTED so ND Analyte NOT DETECTED at or above the reporting limit NR Not Reported dry Sample results reported on a dry weight basis RPD Relative Percent Difference MDL if MDL is not listed,data has been evaluated to the Method Reporting Limit only. Batch Unless specifically stated,all analyses include full Batch QC,including Sample Duplicates,Matrix Spikes and/or Matrix Spike QC Duplicates.in order to meet or exceed method and regulatory requirements. This report contains only results for Batch QC derived from samples included in this report. Complete Batch QC results are available upon request. In cases where there is insufficient sample provided for Sample Duplicates and/or Matrix Spikes,a Lab Control Sample Duplicate(LCS Dup)is analyzed to demonstrate accuracy and precision of the extraction and analysis. 10 Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of 1A custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 8 of 9 ow 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 03/26/08 07:26 - m r- r ?J L py 7j7 i Lt Y! k t 5 S _ f n - -. t LLCL LF C• i E i ,. y � i lLe�g� s e J a� a F 3 ti s LU LU 73 tQ , ss r rrr Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. low 1,$4/1 i Darwin Thomas,Sales/Marketing Page 9 of 9 +tom i Food Quality Labs, Inc. 1 protecting your quality name 6400 SW Canyon Ct., Suite 80. Portland, OR 97221 ka Phone: (503) 297-3636 Fax: (503) 297-3738 www.foodqualitylabs.com For: APEX Labs Case# 08020133 12232 SW Garden Place Rec Date 2/4/2008 Tigard,OR 97223 Tested Date 2/4/2008 to AT TN: Darwin Thomas (503}718-2323 Completed Date 2/4/2008 a802020-01 c ad LAB# Sample Description Turbidity NTU 08020133- A802020-01 C Pond 15 f 01 discharge-1 sampled f 02/02/08 15:10 i i Method 2130D Standard Methods 20th Ed. Reviewed By: Excellence in food testing since 1969 Tuesday,February 26,2008 Page 1 of 1 __ . +rr 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax rrr Tuesday, February 26, 2008 Chris Breemer GeoEngineers 15055 SW Sequoia Pkwy, # 140 we Portland, OR 97224 RE: Tigard Library/4025-003-02 dw Enclosed are the results of analyses for samples received by the laboratory on 2/4/2008 at10:00:00AM. Thank you for using Apex Labs. We appreciate your business and strive to provide the highest quality services to the environmental industry. If you have any questions concerning this report or the services we offer, please feel free to contact me '--,y email at: dthomas(q�apex-labs.com, or by phone at 503-718-2323. r rr r rrri Apex Laboratories 777e results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. au"a/IJ4A� Darwin Thomas,Sales/Marketing Page 1 of r Apex Labs 12232 S.W.Garden Place Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 ANALYTICAL REPORT FOR SAMPLES SAMPLE INFORMATION Sample ID Laboratory ID Matrix Date Sampled Date Received Pond Discharge-1 A802020-01 Water 02/02/08 15:10 02/04%08 10:00 Oil IIS 011 ON �l fill Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of IN custody document.This analytical report must be reproduced in its entirety. )Iau'a/I Darwin Thomas,Sales/Marketing Page 2 of 9 fm 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 ANALYTICAL SAMPLE RESULTS Total Metals by EPA 6020(ICPMS) Reporting Analyte Result MDL Limit Units Dilution Date Analyzed Method Notes Pond Discharge-1 (A802020-01) Matrix: Water Arsenic 0.00112 --- 0.00100 mg/L 1 02/07/08 13:06 EPA 6020 hill rill fill lila flrY lfill Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. fir Darwin Thomas,Sales/Marketing Page 3'of 9 Apex Labs 12232 S.W.Garden Place Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 Kill ANALYTICAL SAMPLE RESULTS (L Conventional Chemistry Parameters Reporting Analyte Result MDL Limit units Dilution Date Analyzed Method Notes Pond Discharge-1 (A802020-01) Matrix: Water Total Suspended Solids 8.00 --- 5.00 mg/L 1 02/06/08 12:43 EPA 160.2 Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. f� Darwin Thomas,Sales/Marketing Page 4 of 9 AV 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 i� QUALITY CONTROL(QC)SAMPLE RESULTS Total Metals by EPA 6020(ICPMS) Reporting Spike Source %REC RPD Analyte Result MDL Limit Units Dil. Amount Result %REC Limits RPD Limit Notes Batch 8020045-EPA 3015 Water Blank(8020045-BLKI) Analyzed:02/07/08 13:01 EPA 6020 1111► Arsenic ND --- 0.00100 mg/L 1 --- --- --- --- --- --- LCS(8020045-BSI) Analvzed:02/07/08 13:03 EPA 6020 Arsenic 0.108 --- 0.00100 mg/L 1 0.111 98 80-120% rlr do rtll 1� il�ll illl ift Apex Laboratories The results in this report apply to the smnples analtTed in accordance with the chain of custody document.This analytical report must he reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 5 of 9 +rr 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 QUALITY CONTROL(QC)SAMPLE RESULTS Conventional Chemistry Parameters 11101 Reporting Spike Source %REC RPD Analvte Result MDL Litnit Units Dil. Amount Result 'S/nREC Limits RPD Limit Notes Batch 8020042-Total Suspended Solids Water Blank(8020042-BLKI) Analyzed:02/06/08 12:43 EPA 160.2 Total Suspended Solids ND --- 5.00 mg/L I --- --- --- --- --- --- will Duplicate(8020042-DUP2) Source:A802020-01 Analyzed:02/06/08 12:43 EPA 160.2 Total Suspended Solids 8.00 --- 5.00 mg/L ] -- 8.00 --- 0 20% Reference(8020042-SRM1) Analyzed:02/06/08 12:43 EPA 160.2 Total Suspended Solids 74.0 --- mg/L 1 80.4 92 90-110% --- I Itl Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of /I custody document.This analytical report nayst he reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 6 of 9 Ilii rrr 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax trr GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkv y,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 SAMPLE PREPARATION INFORMATION �1 ,cx Laboratories Total Metals by EPA 6020(ICPMS) Sample Default RL Prep Lab Number Matrix Method Sampled Prepared Initial/Final Initial/Final Factor EPA 3015 Batch: 8020045 A802020-01 Water EPA 6020 02/02/08 15:10 02/06/08 14:13 45mL/50mL 45mL/50mL 1.00 Conventional Chemistry Parameters Sample Default RL Prep Lab Number Matrix Method Sampled Prepared Initial/Final Initial/Final Factor Total Suspended Solids rr Batch: 8020042 A802020-01 Water EPA 160.2 0211/02/08 15:10 02/06/08 12.43 100mUIN/A 100mL/ImL NA rri +rr err >r�r ■r Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 7 of 9 +rr 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breemer 02/26/08 10:54 Notes and Definitions Qualifiers: Notes and Conventions: DET Analyte DETECTED ND Analyte NOT DETECTED at or above the reporting limit NR Not Reported dry Sanr,'lc results rcp"rtcd dn- RPD Relative Percent Difference MDL If MDL is not listed,data has been evaluated to the Method Reporting Limit only. Batch Unless specifically stated,all analyses include full Batch QC,including Sample Duplicates,Matrix Spikes and/or Matrix Spike QC Duplicates,in order to meet or exceed method and regulatory requirements. This report contains only results for Batch QC derived fi,m samples included in this report. Complete Batch QC results are available upon request. In cases where there is insufficient sample provided for Sample Duplicates an(Por MLttix Spikes,a Lab Control Sample Duplicate(LCS Dup)is analyzed to dcnron�tr to acc��rae and precision of the extraction and analysis. WN Apex Laboratories The results in this report apply to the samples analyzed in accordance i+'ilh the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 8 of 9 r to 12232 S.W.Garden Place Apex Labs Tigard,OR 97223 503-718-2323 Phone 503-718-0333 Fax GeoEngineers Project: Tigard Library 15055 SW Sequoia Pkwy,#140 Project Number: 4025-003-02 Reported: Portland,OR 97224 Project Manager: Chris Breerner 02/26/08 10:54 1111 LU J tL' 'af I z E tu X 1;2 U RAN 5-4 Y-," D LL 0 Is. t' 477 S 6f M t Z W fit F, tu W W to z 0 LJ Z CL �z z A U), U jp—- W (D CC F CL Irr to Apex Laboratories The results in this report apply to the samples analyzed in accordance with the chain of custody document.This analytical report must be reproduced in its entirety. Darwin Thomas,Sales/Marketing Page 9 of 9 I IFood Qualitys, Inc. protecting your quality name 6400 SW Canyon Ct., Suite 80 Portland, OR 97221 Phone: (503) 297-3636 Fax: (503) 297-3738 www.foodqualitylabs.com For: APEX Labs Case# 08030303 ` 12232 SW Garden Place Ree Date 3/14/2008 Tigard,OR 97223 Tested Date 3/14/2008 ATTN: Darwin Thomas s (503)718-2323 Completed Date 3/14/2008 i IN LAB# Sample Description Turbidity NT 03030303- ;303138-01 -- - 52 01 Pond Discharge 2 Method 130B Standard Methods 20th Ed. r rri rrt Reviewed By: _ xcellence in food testing since 1969 Friday,March 14,2008 Page 1 of 1 ill GEOENGINEERS APPENDIX B LEVEL 1 AND 11 ECOLOGICAL RISK ASSESSMENTS r r. wI� APPENDIX B LEVEL I AND II ECOLOGICAL RISK ASSESSMENTS This section presents the results of the Level I Scoping Ecological Risk Assessment (Level I ERA) and the Level II Screening Ecological Risk Assessment (Level 11 ERA)for the site. The Level I and II ERAs were completed in accordance with Oregon Department of Environmental Quality Guidance for Ecological Risk Assessment (DEQ 1998, 2001) as defined in Oregon Administrative Rules (OAR) 340- 122-010 through 340-122-115. A conceptual site model (CSM), shown on Figure 5 in the main body of this report, was developed to identify exposure pathways and receptors at the site. rar The ERAs are based, in part, on historical operational and land use information, and soil/sediment data that were collected during several phases of field work at the site. The primary objective of the ERAs is to assess whether conditions at the site are protective of current and potential future land uses by ecological receptors within the locality of the facility (LOF). rlr 131.0 LEVEL I SCOPING ASSESSMENT A Level I ERA is a conservative qualitative determination of whether ecological receptors and/or exposure pathways are present or potentially present at a site. The Level I ERA is intended to identify sites that are obviously devoid of ecologically important species or habitats and/or where exposure rr pathways are obviously incomplete. A Level I ERA includes assessing existing site data, site visit(s), identification of contaminants of interest (COI), evaluation of receptor-pathway interactions, and completion of a report that summarizes the activities and conclusions of the assessment. A copy of the aw Level I ERA scoping checklist is attached to this appendix. B1.1 Existing Site Data ift The Level I ERA is based, in part, on information presented in other parts of this report. Specifically, the ERA is based on: • Potential contaminant sources (Sections 4.1). • Nature and extent of contamination (Section 4.2). • LOF determination (Section 4.4.1). B1.2 Sensitive Environments low Sensitive or critical habitat [as defined in OAR 340-122-115(49)] includes, but is not limited to, wetlands, habitats required for species listed as threatened or endangered, habitats that are necessary for the continued propagation of important species such as those that are threatened and endangered, essential food sources or nesting sites for other species, spawning and rearing habitats, and county or municipal parks(DEQ, 1998). The site is located in the City of Tigard, Oregon and consists of the Tigard library building, asphalt-paved parking areas and roadways, landscaping; Pinebrook Stream and an associated culvert, the pond, a paved pedestrian trail, riparian and wetland areas (associated with Pinebrook Stream and Fanno Creek), and as areas covered by vegetation (consisting predominantly of grasses, shrubs and trees). Surrounding land is generally vacant or occupied by residential and commercial developments. Site features are shown on Figure 2 in the main body of this report. w File No.4025-003-02 Page B-1 GWENGINEERS� July 11,2008 rrr The U.S. Fish and Wildlife (FWS) National Wetland Inventory (NWI) database was consulted for information regarding wetlands on the site. The FWS identified Fanno Creek as the closest water body to 00 the site. Fanno Creek is adjacent to the eastern and northern portions of the site and flows in an easterly and southerly direction until it discharges into the Tualatin River approximately 2 miles south of the site. The water in Fanno Creek was approximately 2 to 4 feet deep during a March 2007 site reconnaissance. The headwaters of Fanno Creek are approximately 6 miles northeast of the site. As previously discussed in Section 4.4.1, Fanno Creek is not included within the LOF and is not considered in the Level I and II ERAS. t According to an Oregon Division of State Lands (DSL) Removal-Fill permit for the site, a wetland is present in the southeast portion of the site, near Fanno Creek. The DSL permit allows the City to work in and fill a portion of this wetland during planned improvements to Wall Street. The DSL permit also requires the City restore or create additional wetlands as a mitigation measure to these impacts. In addition, the City restored some of the drainage features that discharge into the south swale near the southwest corner of the site. Habitat types at the site are summarized in Figure B-1. B1.3 Species of Special Concern A GeoEngineers biologist contacted the Oregon Natural Heritage Information Center(ONHIC) to request information on listed and proposed species of special concern that may be present at the site. Species of special concern include threatened, endangered, candidate and/or species of concern. The results from the ONHIC database search are included in this appendix. The ONHIC reported 5 records of special concern species (including T&E species) within a 2-mile radius for the Township, Range and Section provided for the site. No records were specific to the site; however, steelhead (Oncorhynchus mykiss) were observed (pre-1999) in Fanno Creek and the Northern Pacific pond turtle (Actinemys marmorata marmorata) was observed off-site in a backwater pond in Fanno Creek near the Tigard City Hall. Table B-1 presents a summary of the species (and their listing status)that have been identified by ONHIC within a 2-mile radius of the site. Species identified by ONHIC as T&E species include: • Steelhead (Oncorhynchus mykiss): Upper Willamette River Winter Run, Fanno Creek, Tualatin River and tributary, a federally threatened species and a state sensitive-critical species. • Coho salmon (Oncorhynchus kisutch): Lower Columbia River ESU, Scappoose Bay, Multnomah Channel, Columbia Slough, Willametter River, a federal-listed threatened species and a state- listed endangered species. Species of concern (non-T&E) identified by ONHIC include: • Townsend's big-eared bat (Corynorhinus townsendii): location unknown, a federal species of concern and a state sensitive-critical species. Habitats in the vicinity of (cave) roosts include Douglas-fir and lodgepole pine forests, ponderosa pine woodlands, Utah juniper-sagebrush scrub, and cottonwood bottomland. • Northern Pacific pond turtle (Actinemys marmorata marmorata): Gemini Pond in Greenway Park and backwater pond in Fanno Creek near Tigard City Hall, a federal species of concern and a state sensitive-critical species. File Alo. 4025-003-02 Page B-2 GEOENGINEER� July 11,2008 i� iw Oregon sullivantia (Sullivantia oregano): location unknown, a federal species of concern and a +r state candidate species. Grows in moist cliffs and basalt derived soil in areas that remain wet to moist most of the year. These findings do not eliminate, nor preclude, the presence of T&E species adjacent to the site but neither 00 steelhead trout or coho salmon are expected to occur on-site based on the absence of suitable habitat within the LOF for either of these species. Similarly, species of concern (non-T&E) identified by ONHIC including Townsend's bat and Oregon sullivantia are not expected occur within LOF based on the absence of suitable habitat for these species. Suitable habitat for the Northern Pacific pond turtle may occur with the LOF during ordinary high water events adjacent to Fanno creek. No survey of the pond turtle or the ordinary high water mark (OHWM) of Fanno creek has been conducted as part of this project. The pond turtle is known not to occur on-site and is currently not listed as a T&E species. B1.4 Contaminants of Interest wr Arsenic is the only COI at the site. ,., B1.5 Observed Impacts Part 2 of the ERA scoping checklist summarizes observable impacts to vegetation and wildlife associated with the site. As previously discussed, the site is generally covered with grasses, shrubs, ruderal areas, overgrown vegetation and riparian areas associated with Fanno Creek. There were no visually obvious impacts to the upland or riparian vegetation or the surface water or sediment associated with Fanno Creek. B1.6 Ecological Features + + Part 3 of the ERA scoping checklist summarizes the evaluation of potential site-related ecological receptors and habitat. The site includes ruderal land (paved areas) and wooded and scrub/shrub/grass habitat. Fanno Creek is adjacent to the site. Pinebrook Stream, associated wetlands, and the pond are err present within the LOF. Several species of birds, plants and insects were observed at the site during the reconnaissance. Most of the species observed are associated with the Fanno Creek wetland/riparian areas. The stream banks are steep and are generally covered with Himalayan blackberry (Rubus L.) and trees (e.g., Red alder and willows; Alnus rubra and Salix sp., respectively). The remainder of the site is comprised of grass- and shrub- covered land, the pond, the library building and paved parking areas. The on-site habitat supports a wide range of species, most of which are associated with the riparian zone of Fanno Creek. Table B-2 lists plants and animals that were observed during the March 5, 2007 site reconnaissance. Figure B-I, in wr the main body of the report, shows ecological features within the LOF and site photographs in Figures B- 2 through B-5 document the different habitat types observed. B1.7 Potential Ecologically Important Species/Habitats Part 4 of the ERA scoping checklist summarizes potential ecologically important species and/or habitat identified at the site. The site reconnaissance confirmed several on-site sensitive habitats including the wetland on the southeast portion of the site and the riparian zone along the west side of Fanno Creek. Birds were observed within the wetland area and along the riparian edge of Fanno Creek during the site reconnaissance. Receptors that may utilize the wetland and riparian habitat within the LOF include a ift variety of plants and urban wildlife including raccoon, opossum, mice and rabbits. Dominant vegetation observed in the riparian zone included non-native Himalayan blackberry and English ivy as well as red w File No.4025-003-02 Page B-3 GMENGINEER� July 11, 2008 alder(Alnus rubra) and swordfern (Polystichum munitum). A list of species observed on-site is presented in Table B-2. 81.7.1 Threatened and Endangered Species gyri The March 5, 2007 site reconnaissance did not include a T&E species survey within the LOF. Two species of federally and state listed T&E species may occur within a 2-mile radius of the Tigard Library based on published information from ONHIC (Table B-1); however, the T&E species identified are known not to occur within the LOF because of a lack of suitable habitat. B1.8 Potential Exposure Pathways Attachment 2 of the ERA scoping checklist summarizes the evaluation of receptor-pathway interactions. Potential exposure pathways at the site include exposure to contaminated soil and sediment, including soil/sediment in wetlands at the southeast portion of the site and in the future channel of the restored Pinebrook Creek. Exposure to contaminated soil may include ingestion, direct contact and inhalation of soil particulates. Refer to the CSM (Figure 5) for a summary of potential exposure pathways. Ali B1.9 Summary The results of the Level I ERA indicate the presence of on-site sensitive habitat as well as potentially l complete receptor-contaminant exposure pathways. Species identified by the ONHIC as T&E species are known not to occur on-site. For the purposes of the Level II ERA, receptor-exposure pathway evaluations are based on non-T&E species. Y B2.0 LEVEL II SCREENING ECOLOGICAL RISK ASSESSMENT The Level II ERA builds on the results of the Level I ERA and initiates the problem formulation process for screening for potential impacts to ecological receptors from hazardous substances at the site. The Level II ERA does not include any field survey activities beyond those conducted during the Level 1 ERA. The results of the Level I ERA indicate the presence of sensitive habitat and associated wildlife. Species of special concern were also identified by ONHIC, but are known not to occur on-site. The Level I ERA also indicates the presence of potentially complete receptor-contaminant exposure pathways. Refer to Figure B-1 for an illustration of habitats at the site and Table B-1 and B-2 for species of special concern within a 2-mile radius of the site and other species observed on-site, respectively. B2.1 2002-2008 Soil/Sediment Data The magnitude and extent of arsenic in soil/sediment at the site was assessed between 2002 and 2008 by Apex Environmental Consulting (Apex), Hahn Associates, Inc. (HAI), and GeoEngineers, Inc. The soil/sediment data collected between 2002 and 2008 are summarized in Table 1, in the main body of the report. The data summary table (Table 1) is the basis of the risk screening completed as part of the Level II ERA. Soil/sediment data included in the risk screening process include those samples that represent: 1) soil left in-place with no existing or proposed pavement, soil or mulch cap and 2) in-place soil with a soil cap less than 2 feet thick. Soil sample data were not included from the following areas: 1) soil that is beneath asphalt, concrete, or imported fill (minimum of 2 feet) in the Wall Street extension and the existing library parking lot, 2) soil beneath the library building, and 3) soil in the Pine Tree Area and Central Tree File No 4025-003-02 Page B-4 GWENGINEERS� July 11,2008 IN Area. The asphalt and mulch caps should be considered preliminary remedies because neither a feasibility +ift study nor a remedial action plan has been completed for the site. It is likely that it will be necessary to modify the mulch caps, if they are selected as a final remedy for contamination in the Pine Tree Area and the Central Tree Area. The risk that arsenic in soil poses to terrestrial receptors was evaluated based on data for samples collected between 0 and 3 feet below existing ground surface (207 samples). The risk that arsenic poses to aquatic receptors was evaluated based on data for samples collected at depths between 0 and 2 feet below existing ground surface within the Pinebrook Stream restoration area and the pond (41 samples). Soil samples collected within the pond were not used in the terrestrial evaluation. Samples from multiple depths at a single location were evaluated as discrete samples during the data evaluation process. B2.2 Candidate Ecological Receptors ww The potential presence of T&E species, their feeding and migratory behaviors, and their preferred habitats were considered to the extent possible, in the selection of site-specific or candidate ecological receptors. Because of a lack of direct evidence suggesting the presence of T&E species on-site, only non-T&E Oft species were considered as potential candidate receptors for the Level 1I ERA process. Site-specific habitat, media and pathways, and candidate receptors are described below and are summarized on Table B-3. rr B2.3 Data Evaluation Soil/sediment samples collected site-wide(with the exception of samples collected within the pond) were used to evaluate the risks arsenic poses to terrestrial ecological receptors. Soil/sediment samples collected within the Pinebrook Stream/wetland area and the pond were used to evaluate the risks arsenic poses to aquatic receptors. The area of the Pinebrook Stream channel that is submerged varies significantly depending on flow; therefore data for soil/sediment samples within the entire restoration area and the pond were used to evaluate arsenic concentrations in submerged soil/sediment and in soil adjacent to the stream. Figure 7 in the main body of the report shows the samples that were utilized to evaluate risks to terrestrial and aquatic receptors. The environmental concentrations(ECs)were defined as the minimum of the 90 percent upper confidence level (UCL)concentration and the maximum detected concentration for each data set. Arsenic is assumed to be evenly distributed within the soil horizon and candidate receptors are assumed to be exposed randomly. rw B2.4 Complete Exposure Pathways +• The purpose of characterizing exposure is to identify those pathways that are complete and are expected to contribute substantially to contaminant exposure by ecological receptors. Complete exposure pathways are pathways that satisfy the following four elements: source, exposure medium, exposure point and wr exposure route. Exposure pathways that meet all four of these elements, and are expected to contribute substantially to a receptor's exposure, are identified as being relevant and complete. The relevant and complete exposure pathways selected are summarized in the CSM presented in the main body of this report(Figure 5). irr File No. 4025-003-02 Page B-5 GWENGINEERS� July 11,2008 rr rr B2.5 Known Ecological Effects The only COI with the potential for ecological exposure is arsenic in soil/sediment. A summary of analytical results for soil are presented in Table 1, in the main body of the report. The toxicity of arsenic to terrestrial organisms is discussed below. B2.5.1 Arsenic In plants, arsenic has been shown to cause wilting, chlorosis, browning, dehydration, mortality, and inhibition of light activation (Eisler, 1988). Arsenic is a carcinogen (cancer-causing), teratogen, and possible mutagen (causing mutations in genes/DNA) in mammals (ATSDR, 1993). Chronic exposure can result in fatigue, gastrointestinal distress, anemia, neuropathy, and skin lesions that can develop into skin cancer in mammals. In birds, tolerance to arsenic varies among species, but effects include destruction of gut blood vessels, blood-cell damage, muscular incoordination, debility, slowness, jerkiness, falling, hyperactivity, fluffed feathers, drooped eyelids, immobility, seizures, and systemic, growth, behavioral, and reproductive problems. Arsenic can cause death in soil microbiota and earthworms. B2.6 Candidate Ecological Assessment Endpoints stir Candidate assessment endpoints represent the proposed link between the receptors that are likely to occur at the site and the ecologically sensitive resources meant to protect them. Candidate assessment endpoints identified for this site include survival and reproductive success of terrestrial vegetation, resident and migratory birds, resident mammals, and terrestrial invertebrate populations(see Table B-3). B2.7 Selection of Contaminants of Potential Ecological Concern Contaminants of potential ecological concern (CPECs) are those COI detected in media that may be present at concentrations resulting in unacceptable risk to ecological receptors. The CPEC selection Will process (or screening) attempts to relate site-specific receptors to site-specific exposure by taking into consideration the actual COI concentrations as well as several other factors that include: 1)the frequency at which the COI was detected; 2) the background or ambient concentration of the COI and 3) toxicity A' and bioaccumulation of the COI. Because arsenic is the only COI at the site, it is only evaluated on an individual basis (not on a cumulative basis). The process of selecting CPEC involved four primary screening steps including (in the following order): frequency of detection (FOD), background ► concentration, chemistry-toxicity and method reporting limit (MRL). The results of the screening steps for soil are discussed below and are presented in Table B-4 (terrestrial soil) and Table B-5 (soil/sediment at the stream/wetland restoration area). 82.7.1 Frequency of Detection DEQ's ERA guidance states "COIs detected in less than 5 percent of the samples site-wide for a given media need not be selected as CPECs." Arsenic was detected in 179 of the 207 samples used for the terrestrial assessment or a detection frequency of 86 percent. Additionally, arsenic was detected in 37 of 41 samples used for the stream/wetland restoration area evaluation or a detection frequency of 90 percent. Arsenic was retained as a potential CPEC, based on the frequency of detection. Ak File No.4025-003-02 Page B-6 GMENGINEERS/ July ll,2008 err B2.7.2 Background Concentration r. The maximum detected concentration (MDC) of arsenic (113 mg/kg) was compared to the DEQ default arsenic background concentration of 7 mg/kg (DEQ, 2002). Because the MDC of arsenic exceeded the ft DEQ default background concentration, arsenic was retained as a CPEO, based on the background comparison. wr B2.7.3 Chemistry-Toxicity Consistent with DEQ Level II ERA protocol, the DEQ Level II Screening Level Values (SLVs) for terrestrial receptors (birds, mammals, invertebrates, and plants) were used to screen against arsenic concentrations in soil at the site. Because only non-T&E species were considered as potential candidate receptors, arsenic was evaluated based on Q=5. That is, arsenic concentrations were compared to the DEQ Level II SLVs multiplied by 5. Arsenic was identified as a terrestrial CPEC because the EC (113 mg/kg)exceeds the plant SLV for non-T&E species of 50 mg/kg. Arsenic concentrations in soil from areas that are submerged or along restored stream banks (and could erode into the stream)were compared to sediment screening levels. Arsenic was identified as a CPEC for the stream/wetland restoration area because the EC (33.4 mg/kg) exceeds the bioaccumulation (7 mg/kg) and freshwater sediment (6 mg/kg) SLVs. Note that the bioaccumulation SLV is intended to evaluate ++� soil/sediment within the stream bed. Arsenic was not identified as a CPEC for the soil adjacent to the stream bank/wetland areas because the EC (33.4 mg/kg) is equal to the probable effects concentration (PEC) of 33 mg/kg. The PEC is intended to risks of evaluate the migration of arsenic in soil to sediment r. in the stream and wetland areas. B2.7.4 Method Reporting Limits iwr The method reporting limits for arsenic were sufficient for detecting arsenic in soil at concentrations less than the SLVs for terrestrial receptors. rr B2.7.5 CPEC Selection Results Results of the Level II ERA at the Tigard library site show that arsenic is retained as a CPEC for terrestrial plants and for soil within the restored strearn bed. +w B2.8 CONCLUSIONS This Level II ERA was completed to assess the conditions, and potential risks to ecological receptors from arsenic in soil/sediment within the LOF. The primary objective of the Level II was to evaluate if rr current conditions at the site were considered protective of existing and potential future ecological use. Ecological receptors that may use the site and be exposed to arsenic in soil include non-T&E species of im plants, mammals, birds, and other terrestrial organisms. T&E species have been identified within a 2-mile radius of the site (ONHIC, 2006), including within Fanno Creek. However, T&E species are known not to occur within the LOF based on a lack of suitable habitat. Terrestrial Evaluation. The Level II ERA concluded that arsenic is a CPEC based on the maximum detected concentration for arsenic (113 mg/kg) exceeding the DEQ Level II SLV for non T&E plants (50 mg/kg). Arsenic concentrations in soil that are based on a site-wide (90 percent UCL) average (11.9 rr mg/kg)do not pose an unacceptable risk to non-T&E plants with in the LOF. it Frle,�'a 4025-003-02 Page B-7 GEOENGINEERS� July 11,2008 rr Aquatic Evaluation. The results of the aquatic evaluation indicate that arsenic is an aquatic CPEC within the proposed stream bed because the arsenic EC within the restoration area, based on the 90 + percent UCL (33.4 mg/kg), exceeds the freshwater sediment SLV (6 mg/kg) and the sediment bioaccumulation SLV (7 mg/kg). The freshwater sediment SLV and the sediment bioaccumulation SLV were used to evaluate sediment within the proposed stream bed. Irw Arsenic was not identified as an aquatic CPEC based on an evaluation of the soil to sediment exposure pathway. The arsenic EC for this exposure pathway within the restoration area, which is also based on the 90 percent UCL (33.4 mg/kg), is equal to the PEC of 33 mg/kg. Therefore, arsenic is not a CPEC for soils adjacent to the proposed stream (i.e., within the wetland area and the stream bank). Irri• B3.0 REFERENCES Agency for Toxic Substances and Disease Registry (ATSDR). 1993. Toxicological Profile for Arsenic. U.S. Public Health Service. Agency for Toxic Substances and Disease Registry. Atlanta, GA. Oregon Department of Environmental Quality, 1998. Guidance for Ecological Risk Assessment, Level I Scoping, Level II Screening (Updated December 2001), Level II Screening Benchmark Values. it Waste Management and Cleanup Division. Oregon Department of Environmental Quality, 2002. Default Background Concentrations for Metals. Memorandum from Toxicology Workgroup to Cleanup Managers. October 28, 2002. Oregon Department of Environmental Quality, 2007. Guidance for Assessing Bioaccumulative Chemicals of Concern in Sediment. Updated April 3, 2007. Oregon Deparment of Environmental Quality/US Environmental Protection Agency, 2005. Portland Harbor Joint Source Control Strategy. December 2005. Oregon Natural History Information Center, 2006. Oregon National Heritage Information Center Database Search: Invoice H-1 11006-AEWI, dated November 10, 2006. U.S. Environmental Protection Agency 2007. Environmental Protection Agency. Internet site. (Accessed April 2007) littp://www.epa.gov/ttn/atw/hltlief/arsenic.html United States Fish and Wildlife Service, 2003. National Wetland Inventory Database. Internet site. (Accessed April 2007) http://www.nwi.fws.gov. irr File No.4025-003-02 Page B-8 GMENGINEERS� July ll,2008 1 GWENGINEERS w rr� r 14�r ECOLOGICAL SCOPING CHECKLIST FA r rr oft .. wr DEQ ECOLOGICAL RISK ASSESSMENT LEVEL I - SCOPING w ATTACHMENT 1 Ecological Scoping Checklist iw Site Name Tigard Library Date of Site Visit 11/2/2006 Site Location Tigard, Oregon aw Site Visit Conducted by Shawn Mahugh and Andrei Karakou Part O as CONTAMINANTS OF INTEREST Adjacent to or Types, Classes, Or Specific Hazardous Substances4 in locality of Known Or Suspected Onsite the facility wr Arsenic X go t As defined by OAR 340-122-115(34) 'As defined by OAR 340-122-115(38) Part 4 OBSERVED IMPACTS ASSOCIATED WITH THE SITE Finding Onsite vegetation (None, Limited, Extensive) E Vegetation in the locality of the site (None, Limited, Extensive) L' Onsite wildlife such as macroinvertebrates,reptiles, amphibians,birds, mammals, other E2 (None,Limited,Extensive) Wildlife such as macroinvertebrates, reptiles, amphibians,birds, mammals,other in the L locality of the site(None, Limited, Extensive) Other readily observable impacts (None,Discuss below) D3 Discussion: 1 —The locality of the site is — 50 %residential,50% vegetation r 2—Limited opportunity for mammals, 1 opossum carcass-possible coyote kill,many birds observed, extensive insect and amphibian habitat 3—Site contains surface water connection to Fanno Creek from large pond rr w err wrr DEQ Ecological Scoping Checklist(Updated January 1998)completed by GeoEngineers,Inc. r DEQ ECOLOGICAL RISK ASSESSMENT LEVEL I - SCOPING ATTACHMENT 1 Ecological Scoping Checklist(cont'd) Part SPECIFIC EVALUATION OF ECOLOGICAL RECEPTORS/ Finding HABITAT Terrestrial-Wooded Percentage of site that is wooded 25% ren Dominant vegetation type(Evergreen,Deciduous,Mixed)—Limited M evergreens planted in front of facility. Prominent tree size at breast height, i.e.,four feet(<6", 6"to 12", >12") 12" atr Evidence/observation of wildlife(Macroinvertebrates, Reptiles, Many birds, 1-macro Amphibians,Birds,Mammals,Other) Terrestrial—Scrub/Shrub/Grasses Percentage of site that is scrub/shrub 45% Dominant vegetation type(Scrub, Shrub, Grasses, Other) G Prominent height of vegetation (<2', 2' to 5',>5') >2' wr Density of vegetation(Dense,Patchy,Sparse) D Evidence/observation of wildlife (None,Macroinvertebrates, Reptiles, 1 mammal, many birds Amphibians,Birds,Mammals, Other) Terrestrial Ruderal(Timber ties,pine trees) Percentage of site that is ruderal 10% Dominant vegetation type (Landscaped,Agriculture, Bare round) L W Prominent height of vegetation(0',>0' to<2',2' to 5', >5') >5' Density of vegetation(Dense,Patchy, Sparse) D Evidence/observation of wildlife (None,Macroinvertebrates, Reptiles, B *a Amphibians,Birds,Mammals, Other) Aquatic—Non-flowing(lentic) Percentage of site that is covered by lakes or ponds (Seasonal Wet <5% to Area/Channel) Type of water bodies (Lakes,Ponds,Vernal pools,Impoundments, Lagoon, P Reservoir, Canal) Size(acres), average depth (feet),trophic status of water bodies 0.1 ac, 1' deep,High T Source water(River,Stream, Groundwater, Industrial discharge,Surface Su water runoff) Water discharge point(None, River,Stream, Groundwater,Wetlands St-Fanno Creek impoundment) Nature of bottom(Muddy, Rocky,Sand, Concrete,Other) M Vegetation present(Submerged, Emergent, Floating) S,E Obvious wetlands present (Yes/No) Y Evidence/observation of wildlife(Macroinvertebrates, Reptiles, B Amphibians, Birds, Mammals, Other) DEQ Ecological Scoping Checklist(Updated January 1998)completed by GeoEngineers,Inc. DEQ ECOLOGICAL RISK ASSESSMENT LEVEL I - SCOPING .r SPECIFIC EVALUATION OF ECOLOGICAL RECEPTORS/ Finding HABITAT Aquatic—Flowing(lotic) (Johnson Creek) Percentage of site that is covered by rivers, streams (brooks,creeks), <5% intermittent streams,dry wash,arroyo,ditches, or channel waterway Type of water bodies (Rivers, Streams,Intermittent Streams,Dry wash, S,I,D,C SW Arroyo,Ditches, Channel waterway) Size(acres), average depth (feet), approximate flow rate (cfs) of water bodies 2' to 3' dee' Bank environment(cover: Vegetated,Bare/slope: Steep, Gradual/height V/G/1 ar (in feet)) Source water(River,Stream, Groundwater, Industrial discharge, Surface R, St, Su water runoff) rr Tidal influence(Yes/No) N Water discharge point(None, River, Stream, Groundwater,Wetlands R impoundment) r Nature of bottom(Muddy, Rocky, Sand, Concrete, Other) M Vegetation present(Submerged,Emergent, Floating) S,E Obvious wetlands present(Yes/No) Y Evidence/observation of wildlife(None,Macroinvertebrates, Reptiles, M,B, Mammals Amphibians,Birds,Mammals, Other) Aquatic-Wetlands (Seasonal Wet Area) .■ Obvious or designated wetlands present(Yes/No) Y Wetlands suspected as site is/has (Adjacent to water body, in Floodplain, A Standing water,Dark wet soils,Mud cracks,Debris line, Water marks) Vegetation present(Submerged,Emergent, Scrub/shrub,Wooded) S,E/S,W Size(acres) and depth(feet) of suspected wetlands 0.1/2' Source water(River,Stream,Groundwater, Industrial discharge,Surface St, Su water runoff) Water discharge point(None, River, Stream, Groundwater,Impoundment) R Tidal influence (Yes/No) N Evidence/observation of wildlife(Macroinvertebrates,Reptiles, B Amphibians,Birds,Mammals,Other) Part O ECOLOGICALLY IMPORTANT SPECIES/HABITATS OBSERVED Quereus garryana—Oregon White Oak Thuja plicata—Western Red Cedar me irw DEQ Ecological Scoping Checklist(Updated January 1998)completed by GeoEngineers,Inc. r DEQ ECOLOGICAL RISK ASSESSMENT LEVEL I - SCOPING ATTACHMENT 2 Evaluation of Receptor-Pathway Interactions EVALUATION OF RECEPTOR-PATHWAY INTERACTIONS Y N U Are hazardous substances present or potentially present in surface waters? X AND Are ecologically important species or habitats present? X AND Could hazardous substances reach these receptors via surface water? When answering the above questions,consider the following: • Known or suspected presence of hazardous substances in surface waters. • Ability of hazardous substances to migrate to surface waters. • Terrestrial organisms may be dermally exposed to water-borne contaminants as a , result of wading or swimming in contaminated waters. Aquatic receptors may be exposed through osmotic exchange,respiration or ventilation of surface waters. • Contaminants may be taken-up by terrestrial plants whose roots are in contact with surface waters. • Terrestrial receptors may ingest water-borne contaminants if contaminated surface waters are used as a drinking water source. Are hazardous substances present or potentially present in groundwater? X AND Are ecologically important species or habitats present? AND Could hazardous substances reach these receptors viagroundwater? When answering the above questions,consider the following: • Known or suspected presence of hazardous substances in groundwater. • Ability of hazardous substances to migrate to groundwater. • Potential for hazardous substances to migrate via groundwater and discharge into habitats and/or surface waters. • Contaminants may be taken-up by terrestrial and rooted aquatic plants whose roots are in contact with groundwater present within the root zone(--lm depth). • Terrestrial wildlife receptors generally will not contact groundwater unless it is discharged to the surface. "Y"= yes; "N"=No,"U" =Unknown(counts as a"Y") trr DEQ Ecological Scoping Checklist(Updated January 1998)completed by GeoEngineers,Inc. DEQ ECOLOGICAL RISK ASSESSMENT wo LEVEL I - SCOPING ATTACHMENT 2 Evaluation of Receptor-Pathway Interactions(cont'd) EVALUATION OF RECEPTOR-PATHWAY INTERACTIONS TV N U Are hazardous substances present or potentially present in sediments? X AND ;, , Are ecologically important species or habitats present? X AND Could hazardous substances reach these receptors via contact with sediments? A, When answering the above questions,consider the following: • Known or suspected presence of hazardous substances in sediment. • Ability of hazardous substances to leach or erode from surface soils and be carried im into sediment via surface runoff. • Potential for contaminated groundwater to upwell through, and deposit contaminants in, sediments. 0 If sediments are present in an area that is only periodically inundated with water, terrestrial species may be dermally exposed during dry periods. Aquatic receptors may be directly exposed to sediments or may be exposed through osmotic exchange, respiration or ventilation of sediment pore waters. • Terrestrial plants may be exposed to sediment in an area that is only periodically inundated with water. 0 If sediments are present in an area that is only periodically inundated with water, terrestrial species may have direct access to sediments for the purposes of incidental ingestion. Aquatic receptors may regularly or incidentally ingest sediment while foraging. r� Are hazardous substances present or potentially present in prey or food items of x ecologically important receptors? AND Are ecologically important species or habitats present? X AND Could hazardous substances reach these receptors via consumption of food items? X When answering the above questions,consider the following: 0 Higher trophic level terrestrial and aquatic consumers and predators may be exposed through consumption of contaminated food sources. • In general, organic contaminants with log Ko, > 3.5 may accumulate in terrestrial mammals and those with a log K0,,>5 may accumulate in aquatic vertebrates. "Y"=yes; "N"=No,"U" =Unknown(counts as a "Y") �r wr gw DEQ Ecological Scoping Checklist(Updated January 1998)completed by GeoEngineers,Inc. DEQ ECOLOGICAL RISK ASSESSMENT LEVEL I - SCOPING ATTACHMENT 2 Evaluation of Receptor-Pathway Interactions(cont'd) EVALUATION OF RECEPTOR-PATHWAY INTERACTIONS Y N U Are hazardous substances present or potentially present in surficial soils? X AND Are ecologically important species or habitats present? AND Could hazardous substances reach these receptors via incidental ingestion of or dermal contact with surficial soils? When answering the above questions,consider the following: • Known or suspected presence of hazardous substances in surficial (—lm depth) soils. • Ability of hazardous substances to migrate to surficial soils. • Significant exposure via dermal contact would generally be limited to organic contaminants which are lipophilic and can cross epidermal barriers. • Exposure of terrestrial plants to contaminants present in particulates deposited on leaf and stem surfaces by rain striking contaminated soils(i.e.,rain splash). • Contaminants in bulk soil may partition into soil solution, making them available to roots. • Incidental ingestion of contaminated soil could occur while animals grub for food resident in the soil, feed on plant matter covered with contaminated soil or while grooming themselves clean of soil. Are hazardous substances present or potentially present in soils? X AND Are ecologically important species or habitats present? AND *a Could hazardous substances reach these receptors via vapors or fugitive dust carried in surface air or confined in burrows? When answering the above questions,consider the following: • Volatility of the hazardous substance (volatile chemicals generally have Henry's Law constant> 10,5 atm-m3/mol and molecular weight<200 g/mol). • Exposure via inhalation is most important to organisms that burrow in contaminated soils, given the limited amounts of air present to dilute vapors and an absence of air movement to disperse gases. • Exposure via inhalation of fugitive dust is particularly applicable to ground-dwelling species that could be exposed to dust disturbed by their foraging or burrowing activities or by wind movement. • Foliar uptake of organic vapors would be limited to those contaminants with relatively high vapor pressures. • Exposure of terrestrial plants to contaminants present in particulates deposited on leaf and stem surfaces. r "Y"=yes; "N"=No,"U"=Unknown (counts as a"Y") w wr DEQ Ecological Scoping Checklist(Updated January 1998)completed by GeoEngineers,Inc. Ibr w GEOENGINEERSL w. r. wr OREGON NATURAL HERITAGE INFORMATION CENTER SPECIES DATABASE SEARCH aw w vo OREGONNATURALHERITAGE INFORMATION CENTER 0SU Oregon State November 10, 2006 Institute for Natural Resources 1322 SE Morrison Street ars Andrei Karankou Portland, Oregon 97214-2423 503.731.3070 GeoEngineers, Inc. http://0regonstate.edu/ornhic ow 15055 SW Sequoia Parkway, Suite 140 Portland, Oregon 97224 r Dear Mr. Karankou: Thank you for requesting information from the Oregon Natural Heritage Information Center(ORNHIC). We have conducted a data system search for rare, threatened and endangered plant and animal records for your Tigard Library Project in Township 2 South, Range 1 West, Section 1 and 2 W.M. Seven(7)records were noted within a two-mile radius of your project and are included on the enclosed computer printout. A key to the fields is also included. Please remember that the lack of rare element information from a given area does not mean that there are no significant elements there, only that there is no information known to us from the site. To assure that there are no important elements present,you should inventory the site, at the appropriate season. This data is confidential and for the specific purposes of your project and is not to be distributed. If you need additional information or have any questions,please do not hesitate to contact me. �., Sincerely, Cliff Alton do Conservation Information Assistant r encl.: invoice (H-111006-AEW I) computer printout and data key wo wr go go rn :r 16 Oregon Natural Heritage Information Center-November 2006 Sensitive Data - Do Not Distribute Scientific Name: Oncorhynchus kisutch pop. 1 Common Name: Coho salmon(Lower Columbia River ESU) Federal Status: LT GRANK: G4T2Q NHP List: 1 Category: Vertebrate Animal State Status: LE SRANK: S2 HP Track: Y ELCODE:AFCHA02031 EO ID: 3164 First Obs: Last Obs: 2001-PRE Confirmed: Directions: SCAPPOOSE BAY,MULTNOMAH CHANNEL,COLUMBIA SLOUGH,WILLAMETTE RIVER County Name Ecoregion Source Feature[Uncertainty Type(Distance)l Clackamas CR Data currently not available. Columbia WV Multnomah 1 IN 10 to ON Tigard Library Project- Page 1 of 6 10 iwP Oregon Natural Heritage Information Center-November 2006 Sensitive Data - Do Not Distribute Town-Range Sec Note QuadCode QuadName Watershed 002N001W 07 45122-05 Oregon City Y 1708000302-BEAVER CREEK 002N001W 03 45122-D5 Gladstone 1709001201-JOHNSON CREEK 002N001 W 06 45122-D6 Lake Oswego 1709001202-SCAPPOOSE CREEK/MULTNOMAH CHANNEL 003N001W 34 45122-E5 Mount Tabor 003N001W 31 45122-E6 Portland 003N001 W 27 45122-E7 Linnton 003N001W 29 45122-1`6 Vancouver irk 003N002W 25 45122-F7 Sauvie Island 003NOO1W 23 45122-FS Dixie Mountain 003N001 W 21 45122-G7 Saint Helens 003N001W 19 45122-G8 Chapman 003N001W 16 45122-1-17 Deer Island 003N002W 13 003N001W 09 003N001W 03 003N002W 01 004N001W 34 004N001W 31 004N002W 36 004NOO1W 28 004N001W 30 004N001W 20 002S002E 30 002SOOlE 24 002S001E 14 002S00lE 11 002S00lE 10 002S00lE 08 002S00lE 03 001S00lE 35 001S001E 27 u11 004N001 W 17 001S001E 10 001N00lE 34 001N00lE 28 UW 001N002E 23 001N00lE 20 004N001 W 10 001N00lE 21 001N002E 24 001N00lE 27 001S00lE 03 001S00lE 15 OO1S00lE 22 001S00lE 26 001S00lE 36 002S00lE 02 wr 002S00lE 09 004N001W 16 002S00lE 17 002S00lE 13 002S002E 19 004N001 W 21 004N001W 29 004N001 W 27 r 004N001W 33 003N002W 02 003N001W 04 to 003N002W 12 003N001W 10 003N002W 14 003N001 W 17 so Tigard Library Project- Page 2 of 6 do Oregon Natural Heritage Information Center-November 2006 Sensitive Data - Do Not Distribute 003N001W 15 003N001W 20 003N001W 22 003N001W 30 003N001 W 28 i 003N002W 36 003NO01W 33 003N001W 35 002N002W 01 002N001W 04 002N002W 12 002NOO1W 18 002NO01W 14 005N001W 34 002N001W 21 002NO01W 23 002N001W 28 002N001W 25 002NO01W 33 002N001W 34 002N001W 36 66 002N00lE 32 001 N001 E 05 001 N00l E 04 004N001W 08 to 001 N001 E 01 001N001W 11 001N00lE 09 001N00lE 11 iw 001N002E 07 001N001W 13 001N001E 17 001N002E 18 go 001N002E 16 001N002E 14 001 N001 E 19 001N002E 15 001N002E 17 001 N001 E 13 001N00lE 18 004N001W 09 001N00lE 12 001NO0lE 10 001 N001 W 12 001N002E 06 001 N001 E 02 001N001E 03 001N00lE 06 001N001W 02 002N00lE 31 002N001W 35 004N001W 03 002N00lE 30 002N001W 27 002NO01W 24 002N001W 22 002N001W 20 002NO01W 13 002N001W 17 Owner Name/Type Owner Comments Managed Area Name illi +itl Tigard Library Project- Page 3 of 6 No Oregon Natural Heritage Information Center-November 2006 Sensitive Data - Do Not Distribute EO Type: REARING&MIGRATION-fish Minimum Elev.(m): Annual Observations EO Data: ODFW DISTRIBUTION MAPS USED TO CREATE THE 1:24,000 COVERAGE. EO Comments: Rearing&migration use.In 2001 Miller Creek,the Columbia Slough and Lake Oswego were added as previous/historic use type.Columbia Slough is diked and has water quality issues so no longer used for rearing.Lake Oswego was historically used for rearing. Protection: Management: General: Distribution information used in this EOR was derived from ODFW geographic resources data produced and distributed in 1999.Unless specific data exists in the data field,the information presented in this EOR represents the"best professional judgement'by ODFW's district fisheries biologist;the presence of coho in described areas should be considered undocumented but as having a potential of being present.EOR was updated using ODFW geographic resources data produced and distributed in 2004. �r Scientific Name: Oncorhynchus mykiss pop. 33 Common Name: Steelhead(Upper Willamette River ESU,winter run) Federal Status: LT GRANK: G5T2Q NHP List: 1 Category: Vertebrate Animal State Status: SC SRANK: S2 HP Track: Y ELCODE:AFCHA02138 EO ID: 1199 First Obs: Last Obs: 1999-PRE Confirmed: Directions: FANNO CREEK County Name Ecoregion Source Feature fUncertainty Type(Distance)l Washington Data currently not available. err Town-Range Sec Note QuadCode QuadName Watershed 45122-D6 Lake Oswego 1709001005-LOWER TUALATIN RIVER 45122-D7 Beaverton rll� Owner Name/Type Owner Comments Managed Area Name EO Type: SPAWNING&REARING-fish Minimum Elev.(m): Annual Observations EO Data: WINTER RUN;ODFW DISTRIBUTION MAPS USED TO CREATE THE 1:24,000 COVERAGE. EO Comments: Protection: Management: General: DISTRIBUTION INFORMATION USED IN THIS EOR WAS DERIVED FROM ODFW GEOGRAPHIC RESOURCES DATA PRODUCED AND DISTRIBUTED IN 2001.UNLESS SPECIFIC DATA EXISTS IN THE DATA FIELD,THE INFORMATION PRESENTED IN THIS EOR REPRESENTS THE'BEST PROFESSIONAL JUDGMENT'BY ODFW'S DISTRICT FISHERIES BIOLOGIST;THE PRESENCE OF STEELHEAD IN DESCRIBED AREAS SHOULD BE CONSIDERED UNDOCUMENTED BUT AS HAVING A POTENTIAL OF BEING PRESENT. Scientific Name: Oncorhynchus mykiss pop.33 Common Name: Steelhead(Upper Willamette River ESU,winter run) Federal Status: LT GRANK: G5T2Q NHP List: 1 Category: Vertebrate Animal State Status: SC SRANK: S2 HP Track: Y ELCODE:AFCHA02138 EO ID: 16447 First Obs: Last Obs: 1999-PRE Confirmed: Directions: TUALATIN RIVER&TRIBUTARY >� County Name Ecoregion Source Feature fUncertainty Type(Distance)l Clackamas Data currently not available. Washington Town-Range Sec Note QuadCode QuadName Watershed 45122-C6 Canby 17090010-Tualatin 45122-D6 Lake Oswego 45122-D7 Beaverton 45122-D8 Scholls 45122-E8 Hillsboro Owner Name/Type Owner Comments Managed Area Name EO Type: MIGRATION-fish Minimum Elev.(m): Annual Observations EO Data: WINTER RUN;ODFW DISTRIBUTION MAPS USED TO CREATE THE 1:24,000 COVERAGE. EO Comments: t�Y Protection: Management: Tigard Library Project- Page 4 of 6 Oregon Natural Heritage Information Center-November 2006 Sensitive Data - Do Not Distribute General: DISTRIBUTION INFORMATION USED IN THIS EOR WAS DERIVED FROM ODFW GEOGRAPHIC RESOURCES DATA PRODUCED AND DISTRIBUTED IN 2001.UNLESS SPECIFIC DATA EXISTS IN THE DATA FIELD,THE INFORMATION PRESENTED IN THIS EOR REPRESENTS THE"BEST PROFESSIONAL JUDGMENT"BY ODFW'S DISTRICT FISHERIES BIOLOGIST;THE PRESENCE OF STEELHEAD IN DESCRIBED AREAS SHOULD BE CONSIDERED UNDOCUMENTED BUT AS HAVING A POTENTIAL OF BEING PRESENT. Scientific Name: Corynorhinus townsendii Common Name: Townsend's big-eared bat Federal Status: SOC GRANK: G4 NHP List: 2 Category: Vertebrate Animal State Status: SC SRANK: S2 HP Track: Y ELCODE:AMACCO8010 EO ID: 26274 First Obs: Last Obs: 1981-PRE Confirmed: Directions: Sensitive Data-contact ORNHIC for more information County Name Ecoregion Source Feature[Uncertainty Type(Distance)] Washington WV Point[Area[-Estimated(800 m)] Town-Range Sec Note Watershed 002SO01W 1709001005-LOWER TUALATIN RIVER 001S001W 001 S001 W 002SO01W Owner Name/Type Owner Comments Managed Area Name No EO Type: Minimum Elev.(m): Annual Observations EO Data: Sensitive Data-contact ORNHIC for more information EO Comments: Protection: 16 Management: General: Museum collection housed at Puget Sound Museum of Natural History(PSMNH). Scientific Name: Actinemys marmorata marmorata 16 Common Name: Northern Pacific pond turtle Federal Status: SOC CRANK: G3G4T3Q NHP List: 2 Category: Vertebrate Animal State Status: SC SRANK: S2 HP Track: Y ELCODE:ARAAD02031 EO ID: 1528 First Obs: 1996-06-10 Last Obs: 1996-06-10 Confirmed: to Directions: Gemini pond in Greenway Park.From Hwy 217,take Scholls Ferry Rd.exit,tum right onto Nimbus,then left onto Gemini Dr.Pond can be accessed from parking lot of 4th building after turning off Nimbus. County Name Ecoregion Source Feature[Uncertainty Type(Distance)l Washington WV Point[Area[-Estimated(400 m)] Town-Range Sec Note QuadCode QuadName Watershed 001 SO01 W 27 45122-D7 Beaverton 1709001005-LOWER TUALATIN RIVER Owner Name/Type Owner Comments Managed Area Name CITY EO Type: Minimum Elev.(m): 46 Annual Observations EO Data: 1996:1 ADULT MALE EO Comments: POND APPROX 500'X 200'NEAR FANNO CREEK,SHALLOW(>T).MAY BE A MITIGATION SITE.SPARSE AQUATIC VEGETATION(CURLY-LEAFED POND WEED)SMALL ISLAND IN POND. Protection: OTHER THAN RIPARIAN CORRIDOR OF CREEK,AREA IS DEVELOPED ON ALL SIDES. Management: General: Scientific Name: Actinemys marmorata marmorata Common Name: Northern Pacific pond turtle Federal Status: SOC GRANK: G3G4T3Q NHP List: 2 Category: Vertebrate Animal State Status: SC SRANK: S2 HP Track: Y ELCODE:ARAAD02031 EO ID: 25504 First Obs: Last Obs: 2002-04-03 Confirmed: Directions: Backwater pond in Fanno Creek behind Tigard City Hall. County Name Ecoregion Source Feature[Uncertainty Tvoe(Distance)] Washington WV Polygon[Negligible(8 m)] Polygon[Negligible(8 m)] Town-Range Sec Note QuadCode QuadName Watershed IN 002SO01W 01 45122-D7 Beaverton 1709001005-LOWER TUALATIN RIVER 002SO01W 02 to Tigard Library Project- Page 5 of 6 Oregon Natural Heritage Information Center-November 2006 Sensitive Data - Do Not Distribute Owner Name/Type Owner Comments Manacled Area Name EO Type: Minimum Elev.(m): 43 Annual Observations EO Data: 1 adult turtle observed basking. iillY EO Comments: Protection: Management: General: Scientific Name: Sullivantia oregana Common Name: Oregon sullivantia Federal Status: SOC GRANK: G2 NHP List: 1 Category: Vascular Plant r State Status: C SRANK: S2 HP Track: Y ELCODE: PDSAXOX020 EO ID: 23424 First Obs: 1978 Last Obs: 1978-05 Confirmed: Y Directions: ON PALISADES,SW CORNER OF OSWEGO LAKE County Name Ecoregion Source Feature[Uncertainty Type(Distance)l Clackamas WV Point[Areal-Estimated(800 m)] Town-Range Sec Note QuadCode QuadName Watershed 0025001E 08 45122-D6 Lake Oswego 1709001201 -JOHNSON CREEK Owner Name/Type Owner Comments Managed Area Name EO Type: Minimum Elev.(m): -339 Annual Observations EO Data: J.SIDDALL MAY 1978 SIGHTING;4 OR 5 PLANTS. ACCESSIBLE ONLY BY WATER; EO Comments: Protection: Management: General: FROM GREENLEAF 1980 ENDANGERED SPECIES STATUS REPORT FOR USFWS 7 records total w rtr err rr rrti Tigard Library Project- Page 6 of 6 rr Key to Oregon Natural Heritage Information Center Data Field Name Description Scientific Name The scientific name of the species. Common Name The common name of the species. Ali Category Value that indicates the broad biological category for each species. ELCODE Unique Heritage Program code for identifying this element. 1st and 2nd byte(PD=Plant dict, PM=Plant monocot, PG=Plant gymnosperm, PP=Plant pteridophyte,AA=amphibian,AB=bird,AF=fish,AM=mammal, AR=reptile, 1=invertebrate. 3rd-5th byte(family abbreviation). 6th-7th(genus code).8th-9th (species). 10th (tie breaker). Federal Status US Fish and Wildlife Service or NOAA Fisheries status.LE=listed endangered, LT=listed threatened,PE or PT=proposed endangered or threatened,C=candidate for listing with enough information available for listing,SOC or SC=species of concern,PS:xx=partial status for species. State Status For animals,Oregon Department of Fish and Wildlife status; LE=listed endangered, PE=proposed endangered, PT=proposed threatened,SC or C=sensitive-critical, SV or V=sensitive-vulnerable, SP or P=sensitive-peripheral, SU or U=sensitive-undetermined status. For plants,Oregon Department of Agriculture status; LE=listed endangered,LT=listed threatened,C=candidate. GRANK/SRANK ORNHIC participates in an international system for ranking rare,threatened and endangered species throughout the world. The system was developed by The Nature Conservancy and is now maintained by NatureServe in cooperation with Heritage Programs or Conservation Data Centers(CDCs)in all 50 states, in 4 Canadian provinces,and in 13 Latin American countries. The ranking is a 1-5 scale, primarily based on the number of known occurrences,but also including threats,sensitivity,area occupied, and other biological factors. In this book,the ranks occupy two lines. The top line is the Global Rank and begins with a"G". If the taxon has a trinomial(a subspecies,variety or recognized race),this is followed by a"T"rank indicator. A"Q"at the end of this line indicates the taxon has taxonomic questions. The second line is the State Rank and begins with the letter"S". The ranks are summarized as follows: 1 =Critically imperiled because of extreme rarity or because it is somehow especially vulnerable to extinction or extirpation,typically with 5 or fewer occurrences;2= Imperiled because of rarity or because other factors demonstrably make it very vulnerable to extinction(extirpation),typically with 6-20 occurrences;3= Rare,uncommon or threatened, but not immediately imperiled,typically with 21-100 occurrences;4=Not rare and apparently secure, but with cause for long-term concern,usually with more than 100 occurrences; 5=Demonstrably widespread, abundant,and secure;H=Historical Occurrence,formerly part of the native biota with the implied expectation that it may be rediscovered;X=Presumed extirpated or extinct;U=Unknown rank;?=Not yet ranked,or assigned rank is uncertain. NHP list All rare species in Oregon are assigned a list number of 1,2, 3 or 4,where 1=threatened or endangered throughout range,2=threatened or endangered in Oregon but more common elsewhere, 3=Review List (more information is needed),4=Watch List(currently stable). A null value indicates the species is not currently on our rare species list. HP Track We currently obtain and computerize locational information for only those elements marked with Y(es). Those species marked with N(o)or W(atch)have incomplete data because we do not actively track them at this time. EO ID Unique identifier for the Element Occurrence(EO). First obs First reported sighting date for this occurrence in the form YYYY-MM-DD. Last—obs Last reported sighting date, usually in the form YYYY-MM-DD. illi Confirmed Indication of whether taxonomic identification of the Element represented by this occurrence has been confirmed by a reliable individual.Blank=unknown,assumed to be correctly identified.Y=Yes,confident identification.?=identification questions. lilt Directions Site name and/or directions to site. County County name(s)in which EO is mapped. lilii Ecoregion Physiographic Province in which EO is mapped:CR=Coast Range,WV=Willamette Valley, KM=Klamath Mountains,WC=West slope and crest of the Cascades,EC=East slope of the Cascades, BM=Ochoco,Blue and Wallowa Mts., BR=Basin and Range,CB=Columbia Basin,SP=Snake River Plains. to irr Key to Oregon Natural Heritage Information Center Data Field Name Description Source Feature A Source Feature is the initial translation of a discrete unit of observation data as a spatial feature. Creation of a Source Feature requires an interpretive process.The likely location and extent of an observation is determined through consideration of the amount and direction of any variability between the recorded and actual locations of the observation data. In most cases,the Source Feature is delineated to encompass locational uncertainty. A Source Feature can be a point,line,or polygon.The type of Source Feature developed depends on both the preceding conceptual feature type and the locational uncertainty associated with the feature. Uncertainty Type The recorded location of an observation of an Element may vary from its true location due to many factors, (Distance) including the level of expertise of the data collector,differences in survey techniques and equipment used, and the amount and type of information obtained.This inaccuracy is characterized as locational uncertainty, and is assessed for Source Feature(s)based on the uncertainty associated with the underlying information on the location of the observation. Four categories of locational uncertainty have been identified,as follows: Negligible uncertainty is less than or equal to 6.25 meters in any dimension.Source Features with negligible uncertainty are based on a comprehensive field survey with high quality mapping and a high degree of certainty. Linear uncertainty is greater than 6.25 meters, and varies along an axis(e.g.,a path,stream, ridgeline).The true location of an observation with linear uncertainty may be visualized as effectively sliding along a line that delineates the uncertainty. Areal delimited uncertainty is greater than 6.25 meters, and varies in more than one dimension.The true location of an observation can be visualized as floating within an area with a boundary that can be specifically delimited.Boundaries can be defined using roads,bodies of water, etc. Areal estimated uncertainty is greater than 6.25 meters,and varies in more than one dimension. A rrr boundary cannot be specifically delimited based on the observation information,i.e.,the actual extent is unknown.The true location of the observation can be visualized as floating within an area for which boundaries cannot be specifically delimited. Source Features with areal estimated uncertainty require that the user specify an estimated uncertainty distance to be used for buffering the feature to incorporate the locational uncertainty. Town-Range,Sec,and United States rectangular land survey(also known as the Public Land Survey System)legal township, Note range, and section descriptions that best define the location of the Element Occurrence. Township first(4 rr bytes), range second(4 bytes). For example: 004SO29E=Township 4S, Range 29E. All locations are with reference to the Willamette Meridian. Fractional ranges or townships are indicated in the Note field. Quadcode USGS code for the USGS topographic quadrangle map(s)where the record is mapped. rrn Quadname Name of the USGS topographic quadrangle map(s)where the record is mapped. Watershed Watershed(s), identified according to the U.S.Geological Survey(USGS)Hydrologic Unit Map 10-digit code, within which the Element Occurrence is located. Owner Name/Type and Federal,State, Private,etc. Comments tirr Managed Area Name BLM District, USFS Forest, Private Preserve EO Type For animals,type of occurrence,eg.roost,nest,spawning,etc. EO Data Species and population biology-numbers,age, nesting success,vigor, phenology,disease, pollinators, etc. EO Comments Habitat information,e.g.aspect,slope, soils,associated species,community type,etc. + Minimum Elevation Minimum elevation of the area covered by the range of the taxon, in meters.-339 or blank=not determined. Annual Observation Summary of yearly observation. Protection Comments on protectibility and threats. Management Comments on how the site is managed. +rr General Miscellaneous comments. ++r TABLE B-1 rir FEDERAL AND STATE OF OREGON SPECIAL STATUS SPECIESI TIGARD LIBRARY 13500 SW HALL BOULEVARD irr TIGARD,OREGON Federally-Listed Threatened Species Common Name Scientific Name Coho Salmon-Lower Columbia River ESU Oncorhynchus kisutch Steelhead-Upper Willamette River Winter Run Oncorhynchus mykiss Federally-Listed Endangered Species Common Name Scientific Name None None rir Federally-Listed Candidate S ecies or S ecies of Concern Common Name Scientific Name Townsend's big-eared bat Corynorhinus townsendii Northern Pacific pond turtle Actinemys marmorata marmorata Oregon sullivantia Sullivantia oregana State-Listed Endangered Species Common Name I Scientific Name Coho Salmon-Lower Columbia River ESU I Oncorhynchus kisutch State-Sensitive-Critical Species Common Name Scientific Name Steelhead-Upper Willamette River Winter Run Oncorhynchus mykiss Townsend's big-eared bat Corynorhinus townsendii Northern Pacific pond turtle Actinemys marmorata marmorata irr State-Candidate Species Common Name . Scientific Name rr Oregon sullivantia Sullivantia oregana Notes: No 'From Oregon Natural History Information Center(2006)published data. i� ire r� File No.4025-003-02 Table 6-1,July 11,2008 GEOENGINEERS r. TABLE B-2 LIST OF PLANTS AND ANIMALS OBSERVED DURING THE LEVEL I ERA SCOPING SITE VISIT TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON Field Survey rw Date: March 05, 2007 Aquatic(5%of site; general aquatic species listed) Algae Gerris species—Common water striders Anas plathyrhynchos—Mallard Branta canadensis—Canada goose Riparian (23%of site; steep slope) r Alnus rubra—Red alder Calamagrostis canadensis—Blue joint Carex species—sedge sp. Cornus stolonifera—Red-osier dogwood Crataegus douglasii—Black hawthorn Equisetum telmatiea—Giant horsetail Festuca occidentalis—Western fescue Geum macrophyllum—Largeleaf avens Ilex aquifolium —English holly Juncus arcticus—Arctic rush Juncus effusus—Common rush Mahonia aguifolium—Tall Oregon grape Rubus discolor—Himalayan blackberry r■ Rubus spectabilis—Salmonberry Rumex crispus—Curled dock Salix scouleriana—Scouler's willow Salix sitchensis—Sitka willow Upland (72%of site) Acer macropjyllum—Bigleaf maple Achilea millefolium—Common yarrow Agrostis capillaris—Colonial bentgrass Arabidopsis thaliana—Mouse-ear cress Arctium minus—Common burdock Cirsium vulgare—Bull thistle Conium maculatum— Poison hemlock Corylus cornuta—Beaked hazelnut r. Cytisus scoparius—Scotch broom Dactylis glomerata—Orchard-grass Daucus carota—Wild carrot �r Deshampsia caespitosa—Tufted hairgrass Equisetum arvense—Common horsetail Fraxinus latifolia—Oregon ash Galium aparine—Common bedstraw Hedera helix— English ivy Holodiscus discolor—Oceanspray Hypericum perforatum—Common St.Johnswort Lupinus polyphyllus— Bigleaf lupine File No.4025-003-02 Table 8-2,July 11,2008 Page 1 of 2 GMENGINEERS. err TABLE B-2 LIST OF PLANTS AND ANIMALS OBSERVED DURING THE LEVEL I ERA SCOPING SITE VISIT err TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON Mahonia nervosa— Dull Oregon-grape Oemleria cerasiformis— Indian plum Pinus monticola—Western white pine Plantago lanceolata—Narrowleaf plantain Poa pratensis—Kentucky bluegrass Polygonum aviculare—Common knotweed P01ystichum munitum—Western sword-fern Populus balsamifera—Black cottonwood Pseudotsuga menziesii—Douglas fir Pteridium aquilinum—Bracken fern Quercus garryana—Oregon white oak Robinia pseudoacacia—Black locust Rosa nutkana—Nootka rose Rumex acetosella—Common sheep sorrel Salix lucida—Pacific willow Sequoiadendron giganteum —Giant redwood Spiraea douglasii—Hardhack Symphoricarpos albus—Common snowberry rr. Taraxacum officinale—Common dandelion Thuja plicata—Western redcedar Trifolium pratense— Red clover Trifolium repens—White clover Tsuga mertensiana—Mountain hemlock Vicia cracca— Bird vetch Viola odorata—Sweet blue violet Whipplea modesta—Whipplevine Various ornamental trees and shrubs from historical landscaping and neighboring residents Corvus brachyrhynchos—American crow Cyanocitta stelleri—Steller's jay Parus atricapillus—Black-capped chickadee Vireo huttoni—Hutton's Vireo Scapanus townsendii—Townsend's mole Port: 4\4025003\02\Finals\402500302Tables.xls IYi wr do Ift File No.4025-003-02 Table B-2,July 11,2008 Page 2 of GWENGINEER� I" TABLE B-3 SITE-SPECIFIC HABITAT, MEDIA/PATHWAYS, AND CANDIDATE RECEPTORS TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON Candidate Receptors Habitat Media: Pathway T&E Non T&E Tigard Library Site grounds- Soil and sediment: Direct Contact, Terrestrial plants, invertebrates, birds, and terrestrial ingestion and particulate emmission N/A mammals Notes: T&E=Threatened and Endangered Species NA= Not applicable for this site. Port: 4\4025003\02\Finals\402500302Ta bl es.xis File No. 3,July 11,2 GMENGINEER Table 8-3,July 11,2008 TABLE B-4 CONTAMINANTS OF POTENTIAL ECOLOGICAL CONCERN ARSENIC IN SOIL TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD,OREGON MRL Detected Compounds Minimum Maximum Minimum Maximum Environmental Concentration Screening Level Value Maximum Sample Detection 90%UCL2 Plants and Birds and Plants4 Invertebrates4 Birds° Mammals4 Retained as CPEC Backgrounds Analyte Sample Group' mg/kg mg/kg mg/kg mg/kg ID Frequency mg/kg Invertebrates Mammals mg/kg mg/kg mg/kg mg/kg (0=5)? mg/kg Arsenic Terrestrial 1.3 3.2 1.98 113 6486-060515-297 179/207 11.9 113 11.9 1 50 300 50 145 Yes(plants) 1 7 T, @ Q=5 1 2.26 0.38 0.24 0.08 Notes: 'Samples used in risk calculations are those representing soil left in-place with no soil or pavement cap or those representing soil left in-place with no cap or with a soil cap less than 2 feet thick. Samples collected from within the retention pond were excluded. 290%UCL was calculated using EPA's ProUCL software(version 4.00.02). The method used to calculate the 90%UCL is the one that ProUCL recommended for calculating the 95%UCL. 3EC for plants and invertebrates is the maximum detected concentration. EC for birds and mammals is the minimum of the 90%UCL and the maximum detected concentration. "Screening level values are based on 0=5 for non-T&E species. The values presented are 5 times the screening level values included in ODEQ(2001):Guidance for Ecological Risk Assessment:Levels I,II,III,IV. 56ackground value referenced is the default background concentration issued in DEQ's Memorandum from Toxicology Workgroup,October 28,2002. Yes(plants)=Compound retained as CPEC because T;i based on Q=5 is greater than 1 for plants. UCL=Upper Confidence Level EC=Environmental Concentration CPEC=Contaminant of Potential Ecological Concern mg/kg=milligrams per kilogram MRL=Laboratory Method Reporting Limit T;;=Risk ratio(EC/SLV)for compound i in medium j. Compound is a CPEC if Ty is greater than 1 and the EC exceeds the background concentration. Q=Receptor designator. Q=1 for Threatened and Endangered(r&E)species;0=5 for non-T&E species. Ti=Sum of Tii for all compounds i. Port: 4\4025003\02\Finals\402500302Tabl es.x Is Table .4,July 11,2 GEoENGINEERS / Table 8-4,July 11,2008 TABLE B-5 CONTAMINANTS OF POTENTIAL ECOLOGICAL CONCERN ARSENIC IN SOIUSEDIMENT AT STREAM/WETLAND RESTORATION AREA TIGARD LIBRARY 13500 SW HALL BOULEVARD TIGARD, OREGON MRL Detected Compounds Minimum Maximum Minimum Maximum S reening Level Value res wa er Maximum Sample Detection 90%UCL2 Environmental Sediment' Bioaccumulation5 PEC6 Retained as CPEC Background? Analyte Sample Group' mg/kg mg/kg mg/kg mg/kg ID Frequency mg/kg Concentration mg/kg mg/kg mg/kg (Q=1)? mg/kg Arsenic Aquatic 1.3 3.2 2 113 6486-060515-297 37/41 33.4 33.4 6 7 33 Yes Bioaccumulation 7 and Sediment Tij @ Q=1 5.6 4.8 1.0 Notes: 'Samples used in risk calculations are those representing soil left in-place in the restored Pinebrook Stream Channel/Wetland Restoration Area and the retention pond. 290%UCL was calculated using EPA's ProUCL software(version 4.00.02). The method used to calculate the 90%UCL is the one that ProUCL recommended for calculating the 95%UCL. 3 E represents the lesser of the maximum detected concentration and the 90%UCL concentration. °Screening level value was taken directly from ODEQ(2001):Guidance for Ecological Risk Assessment:Levels I,11,111,IV. , 513ioaccumulation value was taken directly from ODEA(2007):Guidance for Assessing Bioaccumulative Chemicals of Concern in Sediment. EPEC value was taken from ODEQ/EPA(2005);Portland Harbor Joint Source Control Strategy. 'Background value referenced is the default background concentration issued in DEQ's Memorandum from Toxicology Workgroup,October 28,2002. Yes(Bioaccumulation and Sediment)=Compound retained as CPEC because T;j is greater than 1 for the Bioaccumulation/Background and Freshwater Sediment values and the EC exceeds the background concentration. UCL=Upper Confidence Level EC=Environmental Concentration CPEC=Contaminant of Potential Ecological Concern mg/kg=milligrams per kilogram MRL=Laboratory Method Reporting Limit PEC=Probable Effect Concentrations T;j=Risk ratio(EC/SLV)for compound i in medium j. Compound is a CPEC if T;;is greater than 1 and the EC exceeds the background concentration. Q=Receptor designator. Q=1 for Sediment Evaluation TI=Sum of T;i for all compounds i. Port: 4\4025003\02\Finals\402500302Tables.xls File No.4025-003-02 Table B-5,July ii,2008 GWENGINEER� P:\4\4025003\02\CAD\FinalRI\FigureB1.dwg CWB:MWJ 07/08/08 .. M�dare '19e trees 7¢ a Grass - O Old Large Trees SITE n , M r ., Ir LU UJ II Landscaped v O •�s .,. Z LL e. r Middle Age Trees Ap Landscaped � Middle Age Trees OVA ... Asi Outfall to � t � Fanno Creek Pond t � ' �, Stream/Wetland Restoration Area ► - ?.�O OO 10 0 ILI x Private Property � Outfall N WE S 70 0 70 Feet t s' 3 Site Layout with Ecological Features E Notes: Tigard Library 1.The locations of all features shown are approximate. Tigard, Oregon 2.This drawing is for information purposes.It is intended to assist in showing features discussed in an attached document.GeoEngineers,Inc.can not guarantee the accuracy and content of electronic files. # The master file is stored by GeoEngineers,Inc.and will serve as the official record of this communication. G WEND I N EERS� Figure B-1 Reference:Base drawing provided by Portland Maps. s 1 1 ! 11 Southwest corner of the site,facing southwest. Southwest corner of the site,facing north. iib00 ' i 00 0 0 0 m Pinebrook Stream (prior to restoration). Pinebrook Stream at southeast corner of site(after restoration). U [0 U n a ri [D N m O1 u- N O CO O O LO Site Reconnaissance Photographs N CO O Tigard Library Ecological Risk Assessment to CN C) Tigard, Oregon GWENGINEERS Figure B-2 0 a. M, fie►,' i s Pond in March 2008,facing southwest(high water Outfall from pond to Fanno Creek. conditions). I 00 Q 0 O CD CD m Fanno Creek east of Pond outfall. East stream restoration area, looking west. The driveway to private property south of the site is visible in the U background. m sa U a a ui CO w N CO rn ii N O M O O CDSite Reconnaissance Photographs N O CO Tigard Library Ecological Risk Assessment LO Tigard, Oregon a' i. 0: GWENGINEERS� Figure B-3 0 a Stormwater swale at the north side of the pond, looking Typical shrubs near pond. south. l AAk o 0 ip 0 0 m Eastern portion of site near Fanno Creek, looking west. Grass field north of library,facing south. U m U a Q LO m N CO O LL N O CO O O Site Reconnaissance Photographs N O g Tigard Library Ecological Risk Assessment LO Tigard, Oregon n: o GWENGINEER� Figure B-4 a Northeast portion of the site, near Fanno Creek, looking Pedestrian path at northeast portion of the site, looking east. east. o � 0 m "Pine Tree Area"at main entrance to the library. Parking area at south side of library, looking north. U m U n C, 19 m N m O LL N O M O O Site Reconnaissance Photographs N O CO Tigard Library Ecological Risk Assessment LO Tigard, Oregon a o GWENGINEERS Figure B-5 a � J t r t K o Photograph 21. Northeast Part of Site near Photograph 22. Northeast Part of Site, N Fanno Creek, Facing East. Facing Southeast. C6 Q o' a E Q LL C14 M O N Photograph 23. Landscaping and Drainage Photograph 24. Northwest Part of Site, Slough, Facing South. Fanno Creek, Facing West. 0 x U) N LO O M O O N C) Site Photos ii Tigard Library: CU Ecological/Human Health Risk Assessment F Tigard, Oregon Fi GWENGINEER� g Lai Data Sources: Field photographs collected ure B-6 E November 2,2006 by GeoEngineers field staff. O t� I II Photograph 25. Landscaping from Photograph 26. Landscaping from N Northwestern Part of Site, Facing South. Northwestern Part of Site, Facing Southeast. C6 _ Apr a c m N N f0 ^4 x X rC 1N NLL �if f 1 11. O M LO Photograph 27. Landscaping from Photograph 28. Landscaping near Western Part of Site, Facing South. Library Entrance, Facing East. 0 x N O M O O LON Site Photos a Tigard Library: a Ecological/Human Health Risk Assessment Tigard, Oregon 0 CL GMENGINEER� Data Sources: Field photographs collected Figure B-7 F November 2,2006 by GeoEngineers field staff. 0 f �✓a i5 f �.M r ^ ��, 11 MNO o Photograph 29. Landscaping from Western Part Photograph 30. Landscaping from Central Part N of Library Parking, Facing South. of Library Parking, Facing East. c6 N co 7 7 a N ti f- _as �.. a e v Q 7 Nco :i r o — 2 cl Photograph 31. Southwestern Portion of Site, Photograph 32. South Side of Parking, Landscaping and Drainage Slough, Facing East. Landscaping and Drainage Slough, Facing East. 0 X CO N O co O O N a Site Photos Tigard Library: IL Ecological/Human Health Risk Assessment Tigard, Oregon O GEOENGINEERFI 9ure B-o Data Sources: Field photographs collected November 2,2006 by GeoEngineers field staff. O GEoENGINEERS aw 40 imeI am do Iwo i \ i I i APPENDIX aw COMPILATION OF ANALYTICAL DATA (PROVIDED ON I aw \A \r im No go No V� ,l 'I � \ GMENGINEERS II MW am APPENDixD wo I REPORT wo � i to as am \\\ i APPENDIX D " REPORT LIMITATIONS AND GUIDELINES FOR USE' This Appendix provides information to help you manage your risks with respect to the use of this report. ENVIRONMENTAL SERVICES ARE PERFORMED FOR SPECIFIC PURPOSES, PERSONS AND PROJECTS wr This report has been prepared for the exclusive use of the City of Tigard. This report is not intended for use by others, and the information contained herein is not applicable to other sites. isw GeoEngineers structures our services to meet the specific needs of our clients. For example, an environmental site assessment study conducted for a property owner may not fulfill the needs of a prospective purchaser of the same property. Because each environmental study is unique, each environmental report is unique, prepared solely for the specific client and project site. No one except the City of Tigard should rely on this environmental report without first conferring with GeoEngineers. This report should not be applied for any purpose or project except the one originally contemplated. w. THIS ENVIRONMENTAL REPORT IS BASED ON A UNIQUE SET OF PROJECT-SPECIFIC FACTORS •. This report has been prepared for the Tigard Library in Tigard, Oregon. GeoEngineers considered a number of unique, project-specific factors when establishing the scope of services for this project and report. Unless GeoEngineers specifically indicates otherwise, do not rely on this report if it was: • not prepared for you. • not prepared for your project. • not prepared for the specific site explored. • completed before important project changes were made. If important changes are made after the date of this report, GeoEngineers should be given the opportunity to review our interpretations and recommendations and provide written modifications or confirmation, as appropriate. +err RELIANCE CONDITIONS FOR THIRD PARTIES �. Our report was prepared for the exclusive use of the City of Tigard. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. This is to provide our firm with reasonable protection against open-ended liability claims by third parties with whom there would otherwise be no contractual limits to their actions. Within the limitations of scope, schedule and budget, our services have been executed in accordance with our Agreement with the City of Tigard and generally accepted environmental practices in this area at the time this report was prepared. .r ENVIRONMENTAL REGULATIONS_ARE ALWAYS EVOLVING Some substances may be present in the site vicinity in quantities or under conditions that may have led, or may lead, to contamination of the subject site, but are not included in current .local, state or federal regulatory definitions of hazardous substances or do not otherwise present current potential liability. Developed based on material provided by ASFE,Professional Firms Practicing in the Geosciences;www.asfe.org. w File No. 4025-003-02 Page D-I GWENGINEERS� July 11,2008 Ow GeoEngineers cannot be responsible if the standards for appropriate inquiry, or regulatory definitions of hazardous substance, change or if more stringent environmental standards are developed in the future. SUBSURFACE CONDITIONS CAN CHANGE This environmental report is based on conditions that existed at the time the study was performed. The findings and conclusions of this report may be affected by the passage of time, by manmade events such as construction on or adjacent to the site, by new releases of hazardous substances, or by natural events such as floods, earthquakes, slope instability or groundwater fluctuations. Always contact GeoEngineers 46 before applying this report to determine if it is still applicable. SOIL AND GROUNDWATER END USE to The cleanup levels referenced in this report are site-and situation-specific. The cleanup levels may not be applicable for other sites or for other on-site uses of the affected media (soil and/or groundwater). Note that hazardous substances may be present in some of the site soil and/or groundwater at detectable concentrations that are less than the referenced cleanup levels. GeoEngineers should be contacted prior to the export of soil or groundwater from the subject site or reuse of the affected media on site to evaluate the potential for associated environmental liabilities. We cannot be responsible for potential environmental liability arising out of the transfer of soil and/or groundwater from the subject site to another location or its reuse on site in instances that we were not aware of or could not control. di MOST ENVIRONMENTAL FINDINGS ARE PROFESSIONAL OPINIONS Our interpretations of subsurface conditions are based on field observations and chemical analytical data from widely spaced sampling locations at the site. Site exploration identifies subsurface conditions only at those points where subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data and then applied our professional judgment to render an opinion about subsurface conditions throughout the site. Actual subsurface conditions may differ—sometimes significantly—from those indicated in this report. Our report, conclusions and interpretations should not be construed as a warranty of the subsurface conditions. READ THESE PROVISIONS CLOSELY 66 Some clients, design professionals and contractors may not recognize that the geoscience practices (geotechnical engineering, geology and environmental science) are far less exact than other engineering and natural science disciplines. This lack of understanding can create unrealistic expectations that could 46 lead to disappointments, claims and disputes. GeoEngineers includes these explanatory "limitations" provisions in our reports to help reduce such risks. Please confer with GeoEngineers if you are unclear how these"Report Limitations and Guidelines for Use"apply to your project or site. 0 GEOTECHNICAL, GEOLOGIC AND GEOENVIRONMENTAL REPORTS SHOULD NOT BE INTERCHANGED W The equipment, techniques and personnel used to perform an environmental study differ significantly from those used to perform a geotechnical or geologic study and vice versa. For that reason, a geotechnical engineering or geologic report does not usually relate any environmental findings, conclusions or recommendations; e.g., about the likelihood of encountering underground storage tanks or regulated contaminants. Similarly, environmental reports are not used to address geotechnical or geologic concerns regarding a specific project. File No. 4025-003-02 Page D-2 g GEOENGINEER� July 11,2008 Mi i I BIOLOGICAL POLLUTANTS "" GeoEngineers' Scope of Work specifically excludes the investigation, detection, prevention or assessment of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations, recommendations, findings, or conclusions regarding the detecting, assessing, preventing or abating of Biological Pollutants and no conclusions or inferences should be drawn regarding Biological Pollutants, as they may relate to this project. The term "Biological Pollutants" includes, but is not limited to, molds, fungi, spores, bacteria, and viruses, and/or any of their byproducts. If the City of Tigard desires these specialized services, they should be obtained from a consultant who offers services in this specialized field. wn err r it rr ■r .r .r. a +err MW irr File No. 4025-003-02 Page D-3 GMENGINEERS July Il, 2008