RECORD OF DECISION SELECTED REMEDIAL ACTION. For TEKTRONIX, INCORPORATED EVALUATION AREA 1 BEAVERTON, OREGON ECSI #167

Transcription

1 RECORD OF DECISION SELECTED REMEDIAL ACTION For TEKTRONIX, INCORPORATED EVALUATION AREA 1 BEAVERTON, OREGON ECSI #167 Prepared by OREGON DEPARTMENT OF ENVIRONMENTAL QUALITY Northwest Region Office July 2009

2 1 INTRODUCTION INTRODUCTION SCOPE AND ROLE OF THE SELECTED REMEDIAL ACTION SITE DESCRIPTION AND HISTORY SITE LOCATION PHYSICAL SETTING Climate Geology Hydrogeology Surface Water and Storm Water Features Land Use Beneficial Water Uses Locality of the Facility SITE HISTORY Property Use Regulatory Status Chemical Use and Waste Generation and Management RESULTS OF INVESTIGATION NATURE AND EXTENT OF CONTAMINATION Soil Groundwater Groundwater/Surface Water Interface Surface Water Sediment Indoor/Outdoor Air Fate and Transport of Contamination RISK ASSESSMENT Conceptual Site Model Human Health Risk Assessment Ecological Risk Assessment IDENTIFICATION OF HOT SPOTS Soil Hot Spots Groundwater Hot Spots INTERIM REMEDIAL ACTIONS Building 10/ Building 40 Facility and Surface Impoundments West Park Parcel Groundwater Building 02 Gas Injection Groundwater Extraction at Buildings 40, 16 and i

3 4 PEER REVIEW SUMMARY DESCRIPTION OF REMEDIAL ACTION OPTIONS REMEDIAL ACTION OBJECTIVES Remedial Action Objectives Risk Based Cleanup Levels and Hot Spot Concentrations ESTIMATED VOLUME OF CONTAMINATED MEDIA Groundwater Bank Soil Indoor/Outdoor Air APPLICABLE LAWS AND STANDARDS Oregon Air Pollution Control Rules (OAR ) Oregon Hazardous Waste Management Act (ORS 466) Oregon Solid Waste Management (ORS 459 and OAR and ) Oregon Underground Injection Rules (OAR ) Oregon Water Quality Standards (ORS 468B and OAR ) Oregon Water Pollution Control Act (ORS 468B and OAR ) Oregon Occupational Safety and Health Code (OAR 347) Oregon Water Resource Department Regulations (OAR 690) Archeological and Historical Preservation Act (16 USCA 469a-1) Oregon Noise Control Rules (OAR ) REMEDIAL ALTERNATIVES DEVELOPMENT DESCRIPTION OF ALTERNATIVES Groundwater Alternatives Shallow Soil Alternatives Periodic Monitoring, Review and Contingency Plan EVALUATION AND COMPARISON OF REMEDIAL ACTION ALTERNATIVES EVALUATION CRITERIA PROTECTIVENESS Groundwater Shallow Bank Soil BALANCING FACTORS REMEDIATION OF HOT SPOTS COMPARATIVE ANALYSIS OF BALANCING FACTORS Groundwater Alternatives 2 through Shallow Bank Soil Alternatives 2 and REMEDIATION OF HOT SPOTS SELECTED REMEDIAL ACTION ALTERNATIVE DESCRIPTION OF THE SELECTED ALTERNATIVE ii

4 7.1.1 Confirm Limits of Shallow Soil Contamination and Evaluate Metal Toxicity Engineering Controls for Beaverton Creek: Cap Shallow Soil in Banks Engineering Controls for Building Pilot Testing for Source Area Treatment VOC Source Areas Treatment Implementation of MNA Monitoring Groundwater, Surface Water and Indoor Air Institutional Controls: Easement and Equitable Servitudes, Operations & Maintenance Plan, Remedy Performance Monitoring Plan, Soil Management Plan Periodic Monitoring, Review and Contingency Plan SATISFACTION OF PROTECTION AND BALANCING FACTORS Protectiveness Balancing Factors Remediation of Hot Spots Periodic Review and Contingency Plan FINANCIAL ASSURANCE PUBLIC NOTICE AND COMMENT COMMENTS FROM DEQ RCRA PROGRAM COMMENTS FROM TEKTRONIX INCORPORATED DOCUMENTATION OF SIGNIFICANT CHANGE FINAL DECISION OF THE DIRECTOR DIRECTOR S SIGNATURE ADMINISTRATIVE RECORD INDEX SITE SPECIFIC DOCUMENTS STATE OF OREGON GUIDANCE AND TECHNICAL INFORMATION TABLES Table 3-1 VOCs in Groundwater Compared to Indoor Air RBCs (in text, page 3-2) Table 3-2 Chemicals in Interface Groundwater Compared to SLVs (in text, page 3-3) Table 3-3 Chemicals in Beaverton Creek Sediment Compared to Freshwater Sediment SLVs (in text, page 3-4) Table 3-4 Chemicals of Human Health Concern (in text, page 3-7) Table 3-5 Chemicals of Ecological Concern (in text, page 3-8 Table 3-6 Summary of 2004 analytical Data Relative to Sediment Screening Values (in text, page 3-9) Table 3-7 Summary of 2007 Analytical Data (in text, page 3-10) Table 3-8 Sediment SEM and AVS as Predictors of Toxicity (in text, page 3-10) Table 5-1 RBCs and Hot Spot Criteria (in text, page 5-2) iii

5 Table 5-2 Remedial Action Alternatives Table 5-3 Groundwater Alternative 2 Cost Estimate Groundwater Extraction and Treatment Table 5-4 Groundwater Alternative 3 Cost Estimate Electrical Resistance Heating Table 5-5 Groundwater Alternative 4 Cost Estimate Enhanced Reductive Dechlorination Table 5-6 Bank Soil Alternative 2 Cost Estimate Bank Soil Capping Table 5-7 Bank Soil Alternative 3 Cost Estimate Bank Soil Excavation FIGURES Figure 2-1 Vicinity Map Figure 2-2 Site Plan Evaluation Area 1 Operational Units Figure 2-3 Sanitary, Storm, and Process Waste Lines Figure 2-4 Approximate Sludge Management Areas Figure 3-1 Metals in Surface Soil and SLV Exceedances Beaverton Creek Operational Unit Figure 3-2 TCE Concentrations in Groundwater Layers West - Alternatives 3 and 4 Figure 3-3 TCE Concentrations in Groundwater Layers, East Figure 3-4 Total Metals in Sediment Beaverton Creek Operational Unit iv

6 1.1 INTRODUCTION 1 INTRODUCTION This document presents the selected remedial action for Evaluation Area 1 of the Tektronix Incorporated Beaverton Campus (Tektronix) site at SW Karl Braun Drive in Beaverton, Oregon, which was developed in accordance with Oregon Revised Statutes (ORS) et. Seq. and Oregon Administrative Rules (OAR) Chapter 340, Division 122, Sections 010 through 115. The selected remedial action is based on the administrative record for this site. The Administrative Record Index is presented in Section 8. This report summarizes the more detailed information contained in the Remedial Investigation (RI), Human Health Risk Assessment (HHRA) and Ecological Risk Assessment (ERA) reports, and Feasibility Study Report (FS), all completed under Oregon Department of Environmental Quality (DEQ) Consent Order ESCR-NWR SCOPE AND ROLE OF THE SELECTED REMEDIAL ACTION The selected remedial action addresses the presence of chlorinated volatile organic chemicals (VOCs), semi-volatile organic chemicals (SVOCs) and metals in contaminated soil and groundwater at the Tektronix site. The selected remedial action consists of the following elements: Treatment of contaminants in soil and groundwater through a combination of electrical resistance heating and monitored natural attenuation Engineering Controls: Capping of contaminated bank soil in Beaverton Creek, and contingency measures for Building 38 of application of floor sealant and adjustment of the buildings HVAC system Institutional Controls: Easement and Equitable Servitudes, Remedy Operations and Maintenance Plan, Performance Monitoring Plan, and Soil Management Plan Groundwater, surface water and indoor air monitoring Periodic regulatory performance review and contingency plan 1-1

7 2.1 SITE LOCATION 2 SITE DESCRIPTION AND HISTORY The Tektronix Beaverton Campus is located at Karl Braun Drive in Beaverton, Oregon, Willamette Meridian, sec. 8, T.1S, R.1W, Washington County (see Figure 2-1 Site Location). The site is at latitude and longitude. The Tektronix Campus now comprises 156 acres and has been divided into Evaluation Areas for the purpose of conducting the RI and FS. Evaluation Area 1 (EA1) consists of 10 discrete operational units (see Figure 2-2 Site Plan): West Park and Tracts A through D bracketing Beaverton Creek; Building 02 unit at the southeast corner of the property; Building 40, the industrial waste water treatment facility and Lot 14 units which included the Resource Conservation and Recovery Act (RCRA) treatment, storage and disposal facility; Building 38 unit north of Beaverton Creek and in the center of the property; the Building 16 unit adjacent to the east of the RCRA facility; and Building 04/10/12 unit north of Beaverton Creek and at the eastern property boundary. The Tektronix Campus lies within the Beaverton urban area and is surrounded by commercial and residential properties. Beaverton Creek, a tributary of the Tualatin River, flows east to west through the center of EA1. Most of the Tektronix Campus and EA1 is bounded to the south by a Tri-Met light rail line, to the west by SW Murray Boulevard, and to the east by SW Hocken Avenue. The northern boundary of EA1 is in the center of the Tektronix Campus but is partly bounded by SW Terman Drive. The site is relatively flat with elevations ranging from about 165 feet above mean sea level near Beaverton Creek to 185 feet in the interior of the operational units. About half of the property above the level of Beaverton Creek is covered with either asphalt paved parking lots or large commercial buildings and the rest is grassy and treed landscaping areas. The operational units along Beaverton Creek are unpaved and undeveloped except for the southeastern half of the West Park unit which has been developed recently into commercial use with a series of buildings and paved parking. The Tualatin Hills Nature Park is located along Beaverton Creek about 0.6 miles west and downstream of the Tektronix Campus. 2.2 PHYSICAL SETTING Climate Beaverton, as a part of the greater Portland metropolitan area, receives about 36 inches of precipitation annually. The majority of the precipitation falls between November and April, with monthly totals ranging from 2 to 5 inches, and is highest in January. Precipitation totals for the remainder of the year are generally less than 2 inches per month. The average annual temperature is approximately 55 F Geology The site is underlain from ground surface downwards by the Willamette Silt, the Hillsboro Formation, and the Columbia River Basalt. Because the Columbia River Basalt occurs at great depth it is not of concern for this remedy. The Willamette Silt is approximately 50 feet thick in the site vicinity and consists variably of silt, sandy silt or silty sand. Two distinct subunits of the Willamette Silt have been identified and include an upper brown silt to silty sand commonly with a basal gravel layer, and a lower gray silty sand or sandy silt. The Hillsboro Formation consists of up to 1000 feet of alluvial sediment. The upper portion, encountered during this site investigation, consists generally of brown silty sand to sandy silt. A distinct clay layer was encountered in some borings within the upper 10 feet of the Hillsboro Formation. 2-1

8 2.2.3 Hydrogeology Three distinct water bearing zones, or hydrogeologic zones, have been identified and can be correlated to the upper Willamette Silt, the lower Willamette Silt and the Hillsboro Formation. The three hydrogeologic zones are defined by depth as: shallow from 0 to 28 feet below ground surface (fbgs), intermediate from 29 to 48 fbgs, and deep below 49 fbgs. The water table was encountered at 9 to 26 fbgs, varying with topographic elevation and proximity to Beaverton Creek. The clay layer in the upper portion of the Hillsboro Formation is considered an aquitard. Groundwater within the shallow and intermediate hydrogeologic zones and perhaps the upper part of the deep zone, flows toward and discharges to Beaverton Creek and associated drainage ditches Surface Water and Storm Water Features Beaverton Creek is an urban stream that flows east to west through EA1 and is the main surface water feature in the site area. The creek drains into Rock Creek, which then drains into the Tualatin River. Storm water is collected from paved areas and roof drains through a system of catch basins and storm water lines that drain mainly into Beaverton Creek. The site storm water system is shown on Figure 2-3 Sanitary, Storm, and Process Waste Lines. Several storm water outfalls that drain the interior of the site discharge into Beaverton Creek. Storm water is also collected by minor surface water drainages that flow intermittently from within EA1 and discharge into Beaverton Creek Land Use Land use was evaluated for an area within a 1-mile radius of the site and is documented in Preliminary Scoping Document for Remedial Investigation, Maul Foster and Alongi Incorporated, The Tektronix Campus, including EA1, is zoned by Washington County as industrial. Areas around the site have variable land use designations by both Washington County and City of Beaverton. Industrial and low- and high-density residential uses are to the north of the Campus. Low- and high-density residential, commercial and industrial uses are to the south of the Campus. Commercial and business uses are to the east of the Campus. Multiple-use station communities, high-density residential and industrial uses are to the west of the Campus. The Tualatin Hills Park and Recreation District maintains the Tualatin Hills Nature Park along Beaverton Creek about 0.6 miles to the west. No change in the identified site land use is expected in the foreseeable future for the site or for parcels that have been sold for redevelopment Beneficial Water Uses Surface and groundwater uses have been evaluated for the site area and are also documented in the 2000 scoping document. Current surface water uses for Beaverton Creek include three points of diversion for irrigation use. No current or reasonably likely future users of Beaverton Creek for drinking water were identified. Beneficial uses for Beaverton Creek surface water have been identified as anadromous fish passage and spawning, wildlife, hunting fishing, recreation, and aesthetics. No current groundwater supply wells have been identified on the Campus. Groundwater on the site is not currently used or likely to be used in the future for any beneficial use. Drinking water for the Campus is provided by Tualatin Valley Water District. Water supply wells identified in the site area are located upgradient from the site and screened in deeper hydrogeologic units not impacted by site contamination. The identified supply wells use groundwater for domestic supply, irrigation, and industrial uses. Groundwater in the shallow hydrogeologic unit discharges to Beaverton Creek and therefore has a beneficial use of support of aquatic habitat Locality of the Facility The site Locality of the Facility (LOF) for the EA1 portion of the Tektronix Beaverton Campus consists of all the parcels that compose EA1, all adjacent Tektronix parcels that are part of the current site 2-2

9 property, and the portion of Beaverton Creek that flows through the property including its channel and banks. The LOF for EA1 also includes Beaverton Creek downstream from the site for approximately 1600 feet. 2.3 SITE HISTORY Property Use Tektronix originally occupied about 300 acres beginning in 1957 and developed the site to manufacture, engineer, develop and assemble electronic measurement, display and control equipment. By 1982 the operations included 24 buildings. Since 1994, Tektronix has sold portions of the property to its current size of about 156 acres and 9 buildings in active use. Tektronix no longer conducts manufacturing operations and currently conducts engineering, assembly and recycling operations Regulatory Status Historically, Tektronix has managed hazardous materials and wastes on site and has been subject to regulation under the Resource Conservation and Recovery Act (RCRA), under RCRA Permit number ORD , dated July 25, Tektronix began a facility investigation and corrective action under the RCRA Permit in the late 1980s. On March 29, 2002, Tektronix entered into Consent Order ECSR-NWR to complete a site investigation, develop a feasibility study, and implement remedial actions at the site under DEQ cleanup authority. The corrective action plan and post-closure care requirements of the RCRA permit were referenced in the Consent Order. On June 27, 2006, the RCRA permit was renewed as a post-closure permit, since Tektronix no longer manages hazardous waste, to incorporate the DEQ Consent Order ECSR-NWR for post-closure groundwater monitoring, corrective action and groundwater treatment. All remedial actions, operations and maintenance of the implemented remedy, and performance monitoring are anticipated to be completed under the existing Consent Order. No Further Action (NFA) determinations were issued for the West Park parcel for surface and subsurface soil and groundwater, in 2003 and The NFA actions were based upon a remedial investigation and risk assessment for the parcel. All wells at the West Park parcel were decommissioned after issuance of the 2007 NFS for deep groundwater. The portion of West Park parcel that remains to be addressed under this final remedy includes Beaverton Creek and its banks Chemical Use and Waste Generation and Management Historical releases of hazardous materials have occurred to site soil, groundwater, surface water and sediment in Beaverton Creek. Releases likely have occurred mainly as a result of manufacturing operations, hazardous materials storage and handling, spills and leaks from tanks or other structures, leakage from originally unlined surface impoundments, leakage from underground process waste lines, drying and application of sludge to the ground, and stormwater and groundwater discharge to Beaverton Creek. All potential contamination source areas and known spill or land application areas are documented as required by the RCRA Permit and presented in Remedial Investigation Work Plan, Landau Associates, dated February 7, Process and sanitary wastes were treated and managed on site. An industrial waste water treatment facility (IWWTF) was located on the Building 40 parcel north of Beaverton Creek. Process waste lines, shown on Figure 2-3, converged on the IWWTF. Sanitary wastes were treated in the sanitary waste water treatment facility (SWWTF) shown on Figure 2-3 and located on the Building 04/10/12 parcel. Sludge generated by both the IWWTF and SWWTF were dried and applied to the land on various parcels in EA1 including Buildings 4/10/12 and 16, Tract D near Beaverton Creek and West Park. Areas where sludge has been applied to the land are shown on Figure 2-4, along with the location of the unlined surface impoundments. 2-3

10 Various chemicals have been used on site and include solvents, strippers, paints, photo-resist developers, toxic chemicals, petroleum hydrocarbons, fluoride, acids, caustics and polychlorinated biphenyls (PCBs). Chemical analyses used during the investigation address the following chemicals or groups of chemicals: volatile organic chemicals (VOCs), semi-volatile organic chemicals (SVOCs), metals, cyanide, PCBs, and specialty chemicals (dimethylformamide, formaldehyde, nitrocellulose, hydroquinone). 2-4

11 3 RESULTS OF INVESTIGATION 3.1 NATURE AND EXTENT OF CONTAMINATION Site investigation and characterization began in the 1980s under the RCRA Permit and has continued under the existing Consent Order. The investigation has been completed for all 10 parcels that comprise EA1. For the West Park parcel only Beaverton Creek will be discussed in this document since the upland areas and groundwater has been addressed through the issuance of NFAs. The site investigation was conducted in several phases. Phase I included soil and groundwater sampling across the site to establish the list of chemicals for analysis and investigate all known sources of contamination. Phase II included additional investigations to address data gaps identified during Phase I. Phase III included sampling sediment, groundwater/surface water interface water, and surface water in Beaverton Creek. Phase IV included installation of groundwater monitoring wells to complete the area groundwater evaluation for gradient and seasonal variation. Phase V included indoor air monitoring for Building 38 where elevated concentrations of VOCs in groundwater were known to exist near and beneath the building. Results of the Phase I work are presented in Technical Memorandum: Phase 1a Evaluation, dated April 8, 2003, and Phase I Data Report, dated December 11, 2003, Landau Associates. All results of the remedial investigation are presented in Remedial Investigation Report (RI), Dated March 23, 2007, Landau Associates. Areas of the site where metals contamination was detected at elevated concentrations include: soil at the IWWTF, and Beaverton Creek bank soil and sediment. Areas where VOCs were detected at elevated concentrations include: in groundwater at Buildings 2, 10, 38 and 40, soil and groundwater at the IWWTF and former surface impoundments, and in surface water in Beaverton Creek. Elevated concentrations of SVOCs were detected in sediment in Beaverton Creek. Sample analytical results for soil, bank soil, sediment and groundwater are summarized in Tables 5-1 through 5-7 in the RI. The following is a discussion of the nature and extent of contamination in impacted media at EA Soil Soil was sampled across EA1 (outside of Beaverton Creek valley) in areas identified as potential contamination source areas (Remedial Investigation Work Plan, February 7, 2003, Landau Associates), and analyzed for metals, VOCs, SVOCs and specialty chemicals. Depths of sampling included shallow soil from 0 to 3 fbgs and deep soil at greater than 3 fbgs. Analytical results were compared to U.S. Environmental Protection Region 9 Preliminary Remediation Goals (PRGs) for occupational direct contact and to soil background concentrations for metals. Arsenic and chromium exceeded occupational PRGs in shallow soil at the IWWTF. Chromium and tetrachloroethene (PCE) exceeded the PRGs in deep soil also at the IWWTF. The maximum detected concentration for arsenic in soil is 6.75 milligrams per kilogram (mg/kg) which is below the area background concentration of 7 mg/kg (DEQ Memo, Default Background Concentrations for Metals, October 28, 2002). Chromium was detected in shallow and deep soil at up to 7,140 and 1,010 mg/kg, respectively. The chromium RBC exceeded was 210 mg/kg, which is a screening value formerly used by U.S. EPA region 9, which assumes a given ratio of hexavalent to trivalent chromium. The current U.S. EPA industrial screening value (as of November 2008), assuming a mixture of trivalent and hexavalent chromium is 1,400 mg/kg. It is more common of chromium in soil to be almost entirely trivalent, and the current screening value for trivalent chromium is 120,000 mg/kg. No human health risks were identified for chromium in soil (Section 3.2.2). PCE is the only VOC detected in shallow or deep soil at a concentration that exceeds the occupational RBC. This detection was at 4.5 fbgs at the IWWTF. No other VOCs, SVOCs or specialty chemicals were detected in soil at elevated concentrations. 3-1

12 Beaverton Creek shallow bank soil was sampled and analyzed for metals (see Figure 3-1 Metals in Surface Soil). The results were compared to DEQ screening level values (SLVs) for freshwater sediment because the soil is potentially subject to erosion from scouring during flood stage. Additionally, bank soil was evaluated for ecological risk and exceeded default terrestrial ecological SLVs in a Level II assessment. (Ecological Risk Assessment, Landau Associates, 2007, see Section 3.2.3). Five metals exceed their respective ecological SLVs include cadmium, copper, mercury, nickel and zinc. In addition, chromium, lead and zinc exceeded estimates of background, which themselves are greater than the terrestrial ecological SLVs. All the foregoing metals exceeded freshwater sediment SLVs; these exceedances were further considered in sediment risk assessment (see Section ). Areas where metals concentrations exceeded terrestrial ecological SLVs in bank soil include West Park parcel and Tract C. Metals are present in bank soil likely because of re-deposition of suspended sediment, as a result of previous creek flood scouring or overland flow of stormwater from upland areas particularly near areas of historical land application of sludge Groundwater Groundwater data was collected from the three identified hydrogeologic zones: shallow - from the water table to 28 fbgs; intermediate - from 29 to 48 fbgs; and deep - greater than 48 fbgs. Groundwater sample results were compared to RBCs for the vapor intrusion to indoor air pathway for occupational workers. Drinking water is not a beneficial use for groundwater at the site, and therefore the vapor intrusion exposure pathway is the primary source of risk from VOCs in groundwater. VOC contaminant plumes are present in groundwater beneath Buildings 2 (Tract D), 10, 16, 38 and 40, the IWWTF and SWWTF, former surface impoundment area, and in Tract C within the channel of Beaverton Creek. The distribution of all detected VOCs can be represented by the distribution of TCE plumes as shown on Figures 3-2 and 3-3. The following Table 3-1 shows the VOCs present in the three hydrogeologic zones that exceed tap water PRGs (as screened initially in the RI) compared to RBCs for the vapor intrusion pathway since this pathway is the primary complete risk driver for the site. Table 3-1VOCs in Groundwater Compared to Indoor Air RBCs VOCs in Groundwater that Exceed Tap Water PRGs. Groundwater Concentrations (ug/l) Vapor Intrusion RBCs (ug/l) Shallow Intermediate Deep 1,1,2,2-Trichloroethane NA 1,1,2-Trichloroethane ND 670,000 1,2-Dichloropropane ND NA Benzene ,700 Bromodichloromethane 1.07 ND ND 11,000 Chloroform ,100 Cis-1,2-Dichloroethene 194, ,000 12, ,000 Dichlorofluoromethane NA Tetrachloroethene ND 1,300 Trichloroethene 55, , , Vinyl Chloride 5,650 10,600 6, Ethylbenzene ,000 Total Xylene >S Toluene >S Notes: NA value not available; ND not detected; >S value greater than chemical solubility limits; shaded cells are chemical concentrations that exceed DEQ generic RBCs for vapor intrusion pathway from Risk-Based Decision-Making (DEQ, 2008) 3-2

13 Concentrations of VOCs and SVOCs detected in all groundwater zones were highest in the area of the IWWTF and former unlined surface impoundments, with concentrations generally decreasing with depth; except for benzene, TCE, vinyl chloride, xylene and toluene, which all increase in concentration in the intermediate zone then decrease into the deep zone. TCE and vinyl chloride exceed vapor intrusion pathway RBCs in the each of the three hydrogeologic zones. SVOCs, bis(2-ethylhexyl)phthalate and pentachlorophenol, were detected at elevated concentrations but will not contribute to the indoor air pathway, since these compounds are non-volatile Groundwater/Surface Water Interface Groundwater samples were obtained from the groundwater/surface water interface zone, in Tract C near the groundwater plume beneath Beaverton Creek (see Figure 3-2) and prior to discharge of groundwater to surface water. This data, along with surface water data, was screened against tap water PRGs in the RI to select COPCs for evaluation of the Beaverton Creek recreational user pathway and the COPCs were then carried forward into the risk assessment (see Section 3.2.2). Contaminants detected in interface groundwater samples were compared to DEQ SLVs for aquatic receptors. Dissolved metals detected in interface groundwater include cadmium, chromium, copper, nickel and zinc. These concentrations are generally higher than concentrations for these metals in the interior of the site. VOCs detected at elevated concentrations include PCE, TCE, and cis-1,2-dce. These five metals and cis-1,2-dce exceed DEQ s SLVs for aquatic receptors as shown on Table 3-2. Table 3-2 Chemicals in Interface Groundwater Compared to SLVs Chemicals in Interface Groundwater Maximum (mg/l) Aquatic SLV (mg/l) Metals Cadmium Chromium Copper Nickel Zinc VOCs Cis-1,2-Dichloroethene Tetrachloroethene (PCE) Trichloroethene (TCE) Surface Water Dissolved metals detected in surface water include chromium, copper, lead, nickel and zinc. Only copper and lead exceed aquatic SLVs at and mg/l, respectively. VOCs detected in surface water include chloroform, cis-1,2-dce, toluene and TCE, all detected at concentrations below 3 ug/l and below aquatic SLVs. Fluoride was also detected at concentrations up to 0.5 mg/l, and was subsequently determined to be consistent with ambient background levels (see Section ). Chloroform was detected in 11 of 12 samples with the highest concentration (0.79 ug/l) detected in an upstream sampling 3-3

14 location. The highest concentration of TCE (2.02 ug/l) was detected in Tract C, just downstream from the groundwater plume present beneath Beaverton Creek, with concentrations decreasing a short distance downstream Sediment Investigation of sediment in Beaverton Creek included sampling sediment within the creek channel, as well as a limited number of samples collected from surface drainage ditches east of the IWWTF area that flow into Beaverton Creek. Beaverton Creek sediment data includes samples collected prior to 2002, and those collected between 2002 and Metals and PAHs are the main contaminants detected in Beaverton Creek sediments (see Table 3-3). Metals present in sediment at concentrations that exceed freshwater sediment SLVs include cadmium, chromium, copper, lead, mercury, nickel, and zinc. Metals concentrations generally increased from upstream of the property through Tract C, and decreased farther downstream. However, concentrations of metals in sediment were elevated above the upstream background concentrations for a distance of about 1600 feet downstream from the western property boundary (see Figure 3-4). Several PAH constituents were detected in sediment at concentrations that exceed their aquatic SLVs. Cyanide was also detected in 10 out of 58 samples at a maximum concentration of 3.54 mg/kg, but does not have a sediment SLV for comparison. Table 3-3 Chemicals in Beaverton Creek Sediment Compared to Freshwater Sediment SLVs Chemicals in Beaverton Creek Sediment Maximum Sediment SLV (mg/kg-dry wt) Estimated Background a Metals (mg/kg) Cadmium Chromium b Copper Lead Mercury Nickel Silver Zinc 1, c Volatiles (mg/kg) 1,1-Dichloroethane NA NA Cis-1,2-Dichloroethene 1.29 NA NA Chloroethene NA NA Ethylbenzene NA NA Toluene NA NA 3-4

15 Semivolatiles (mg/kg) Anthracene NA Benzo(a)anthracene NA Benzo(a)pyrene NA Benzo(ghi)perylene NA Benzo(k)flouranthene NA Chrysene NA Dibenzo(ah)anthracene NA Fluoranthene NA Fluorine NA Ideno(1,2,3-cd)pyrene NA Phenanthrene NA Pyrene NA Naphthalene NA Other Chemicals Cyanide 3.54 NA NA Notes: NA criteria not available a From Guidance for Assessing Bioaccumulative Chemicals of Concern in Sediment (DEQ 2007) and Default Background Concentrations for Metals (DEQ 2002) b Site specific estimate c Estimated by Washington DOE, Clark County, Washington Indoor/Outdoor Air Both indoor and outdoor air sampling was conducted during December 2004 and May 2005 to establish a site-specific background concentration and to evaluate indoor air conditions within Building 38. Building 38 is not currently occupied by workers and will not be occupied until after the completion of site cleanup, but overlies a groundwater contamination plume in the shallow hydrogeologic zone. Outdoor air samples were collected from several buildings within EA1 and from parcels adjacent to Building 38. The samples were analyzed for PCE, TCE, cis-1,2-dce, trans-1,2-dce, 1,1-DCE and vinyl chloride. TCE was detected on the roofs of Buildings 19, 38, 39 and 48 at concentrations ranging from 0.04 to micrograms per cubic meter (ug/m 3 ); no other chemicals were detected during this event. PCE, TCE and 1,1-DCE were detected on the roof of Building 73 at concentrations of 0.49 ug/m 3, 4.2 ug/m 3, and ug/m 3, respectively. Nine indoor air samples were obtained from Building 38, representing the three levels of the building and were compared to the occupational RBC of 0.1 ug/m 3. TCE was detected at concentrations that exceed the indoor air RBC in all nine samples, ranging from 2.1 to 14.0 ug/m 3 for the first floor, 2.2 and 2.9 ug/m 3 for the second floor, and 2.4 ug/m 3 for the third floor. 3-5

16 3.1.7 Fate and Transport of Contamination PCE and TCE, and their degradation products cis-1,2-dce and vinyl chloride, are the main chemicals that are detected in groundwater beneath the site. These chemicals are present in the subsurface with a vertical extent to the deep groundwater zone. Release of dense non-aqueous phase liquids (DNAPLs) is the most likely cause for the vertical distribution of VOCs present at the site. Because DNAPLs are denser than water, they tend to migrate downward until they reach a state of equilibrium. The conclusion of the RI is that DNAPL migration is not an ongoing process although residual DNAPL contamination likely comprises a portion of each of the groundwater plume source areas. Groundwater plumes have been identified in several areas within EA1. The migration mechanism for groundwater plumes is most likely by advection and plume movement would tend to be consistent with groundwater flow. The rate of horizontal groundwater flow has been calculated for the site at 5 to 50 feet per year. However, the plumes appear to be moving more slowly than the rate of groundwater flow as a result of several factors including the low permeability of the Willamette Silt and Hillsboro Formation, retardation of dissolved contaminants through adsorption to formation materials, active degradation of contaminants as evidenced by the presence in substantial concentrations of cis-1,2-dce and vinyl chloride (degradation products of PCE and TCE), and also by the operation of existing groundwater containment systems. Vapor transport of VOCs from shallow groundwater into soil and then into onsite buildings is a likely migration pathway considering the presence of VOCs in shallow groundwater and also measured in indoor air. Movement of VOCs in the vapor phase in soil is likely limited to diffusion because of the low potential advective air flow within the Willamette Silt. VOCs in shallow and intermediate groundwater discharge to Beaverton Creek surface water. Because of the high volatility of VOCs their presence in surface water will tend to be short lived. Sampling of surface water has documented low concentrations at points of discharge within Tract C and decreasing concentrations within a short distance downstream. Metals are present in Beaverton Creek sediment but they are generally stable under normal stream flow. There may be potential for scouring and transport downstream during high velocity storm flow conditions. Based on lack of significant concentrations of metals in surface water, the metals in sediment do not appear to be partitioning from sediment to surface water. 3.2 RISK ASSESSMENT Human health and ecological risk assessments were conducted for EA1 and are presented in Human Health Risk Assessment, Tektronix Inc., Beaverton, Oregon, dated August 17, 2006, and Ecological Risk Assessment, Tektronix, Inc., Beaverton, Oregon, both by Landau Associates Inc. Additional evaluation of Beaverton Creek sediment toxicity was performed for the ecological risk assessment and is summarized in Technical Memorandum: Phase 3 Sediment Chemistry and Toxicity Testing at Beaverton Creek Operational Unit, dated October 9, 2007, by WindWard Environmental LLC Conceptual Site Model The Tektronix Beaverton campus is industrial, and the surrounding land use is a combination of commercial and residential. No water supply wells are located on the campus. Shallow groundwater discharges to Beaverton Creek which flows westerly through the campus where it intercepts several outfalls and onsite surface water drainages. Based on these existing and reasonably likely future land 3-6

17 uses, the potential receptors evaluated in the risk assessment are site workers, hypothetical future construction and excavation workers, recreational visitors using Beaverton creek and offsite residents 1. The ecological risk assessment evaluated both aquatic and terrestrial ecological receptors. Terrestrial organisms (birds and mammals) may be exposed to contaminants in surface soil. Additionally, during the site investigation, it was assumed that shallow groundwater at the site may discharge to the Beaverton Creek and therefore, aquatic organisms may be exposed to contaminants in groundwater discharging to interstitial water in sediment or surface water. Both surface water and sediment were evaluated as part of the ecological risk assessment and follow-on sediment toxicity evaluation Human Health Risk Assessment The human health risk assessment addressed potential direct contact exposure to contaminants in surface soil or inhalation of volatile contaminants from soil or groundwater or soil particulate to site workers or future construction and excavation workers. Direct contact exposure to Beaverton Creek surface water and sediment was considered as potential exposure to off-site residents using groundwater as a potable water source Pathway Analysis The human health risk assessment evaluated five groups of potential exposed people, as follows: construction workers, industrial workers, excavation workers, residential visitors and offsite residents. Offsite residents were evaluated for a hypothetical drinking water scenario. However, since groundwater contamination is not migrating offsite and the LOF does not include offsite residential areas, this pathway is not used for determination of remedial action goals or cleanup levels. Recreational visitors were evaluated for a hypothetical swimming scenario that included contact with Beaverton Creek surface water and sediments. The remaining worker scenarios consider exposure to soil and groundwater onsite, either by direct contact or indirectly through inhalation of vapors migrating from the subsurface Chemicals of Concern All applicable data from the RI were used to characterize soil, sediment, surface water and indoor air and included in the risk assessment. Outdoor air concentrations of volatile contaminants were estimated based on concentrations measured in soil and groundwater in the RI. The site data were screened to identify chemicals of potential concern (COPCs). The detected chemicals were screened for frequency of detection (FOD), estimates of naturally-occurring background concentrations of metals, and lastly screened against risk-based concentrations (RBCs) to identify contaminants of potential concern (COPCs). The results of the human health risk assessment estimated that cumulative carcinogenic risk to occupational workers was 9 x 10-5, exceeding the acceptable risk level. Most of this potential risk was associated with Trichloroethene (TCE) volatilized from groundwater. All other COPCs had risk estimated below 1 x Non-cancer risks estimated for excavation workers were estimated at a hazard index of 7, which exceeds the acceptable hazard index of 1. Similarly, the cumulative carcinogenic risk was estimated at 1 x Risks were primarily associated with dermal contact with TCE in groundwater. No other COPCs resulted in risk predictions exceeding 1 x10-6 or a hazard index of 1. No unacceptable risks were associated with exposure to soil. 1 Offsite residents evaluated for a hypothetical groundwater use scenario only. Because contaminated groundwater is not migrating off-site, this pathway is incomplete and is not used for determination of applicable cleanup levels or RAOs for the site. 3-7

18 For the recreational visitor, risk was estimated at 1x 10-5, and associated with dermal exposure to TCE in surface water. Benzo(a)pyrene risk at 4 x 10-6 was estimated in this scenario associated with sediment, which exceeded the acceptable threshold. However, DEQ s review of the polyaromatic hydrocarbon (PAH) data, including benzo(a)pyrene, revealed that samples with the highest concentrations of PAHs including benzo(a)pyrene were collected near roadways across Beaverton Creek and/or parking lots. Other samples showed concentrations similar to upgradient background samples. It is DEQ s opinion, based on this review, that the slightly elevated risk estimate is not representative of the reach of Beaverton Creek on the Tektronix campus as a whole, and that this risk is unlikely to be related to historic waste disposal practices. Exposure pathways posing risk exceeding acceptable levels are vapor intrusion into buildings, dermal exposure to surface water for a hypothetical recreational swimmer and dermal contact with groundwater for an excavation worker There is concurrence between each of the exposure scenarios evaluated indicating the substance that is primarily determining risks at the site is TCE. Based on the risk assessment results, the human health chemical of concern (COC) by media is shown in Table 3-4. Table 3-4 Chemicals of Human Health Concern COC Groundwater Surface Water Indoor Air Trichloroethene (TCE) x x x a a - Risks predicted for outdoor air as well, occupational worker scenario (3x10-6 ) Ecological Risk Assessment An ecological risk assessment was performed for the site that considered both terrestrial and aquatic components. The terrestrial risk assessment considered risks to wildlife (birds and mammals) that might be exposed to surface soil on the site. The aquatic assessment considered risks to aquatic life that might be exposed to surface water, groundwater discharging to surface water and sediment. Additionally, aquatic dependent wildlife (e.g., herons) was also considered Pathway Analysis The environmental media of concern are surface soil, surface water and sediment in Beaverton Creek. The site data were screened to identify chemicals of potential ecological concern (CPECs). The detected chemicals were screened for FOD, estimates of naturally-occurring background concentrations of metals, and lastly screened against ecological screening level values (SLVs). A bioaccumulation screening was also performed. The ecological assessment considered whether risk might result from exposure of aquatic life, including benthic invertebrates, to CPECs in surface water or sediment in Beaverton Creek. Aquatic dependent life (e.g., waterfowl or wading bird) that might be exposed to Beaverton Creek surface water or sediment were also considered. Finally, potential risks to birds and mammals from surface soil exposure were considered. The ecological assessment considered risk to aquatic life through exposure to contaminants in interface groundwater discharging to surface water in Beaverton Creek. As described in section 3.1.3, groundwater near the surface water interface was screened against aquatic ecological criteria, as part of the RI. Chemicals that exceeded these criteria were five metals and one VOC (see Table 3-2). The risk potential addressed by this screening is the possibility that contaminants in groundwater might migrate to sediment porewater where sediment-dwelling aquatic organisms may be exposed. For the five metals that exceeded criteria, this risk potential was evaluated directly through additional sediment toxicity evaluation described in section Since bulk sediments in Beaverton creek are in equilibrium with all sources, 3-8

19 including any potential groundwater discharges, the sediment evaluation provides a sufficient basis to conclude that contaminant contributions from groundwater to sediment, if any, pose negligible risk. Cis-1,2-Dichloroethane also exceeded the aquatic criteria by this pathway by approximately a factor of two. It is unlikely that after further advection and dispersion into the sediment porewater, Cis-1,2-DCE concentrations would remain at concentrations posing unacceptable risk to aquatic organisms. However, because remedial action objectives for the site will reduce VOC concentrations (see Section 5.1.1), cis- 1,2-DCE in shallow groundwater will also be reduced, thereby reducing any risk potential that could exist by this pathway Chemicals of Ecological Concern Based on site history and previous investigation the constituents of ecological concern are VOCs, metals, SVOCs, cyanide, PCBs, and fluoride. Table 3-5 Chemicals of Ecological Concern COEC Soil Surface Water Cadmium X Chromium X Copper X X Lead X X Mercury X Silver X Zinc X X Additional evaluation was performed to assess all CPECs in sediment and the significance of fluoride in surface water. The sediment evaluation considered the significance of bank soils as a source to sediment, and potential for contributing to any risk by this pathway. The sediment toxicity evaluation is discussed in Section and fluoride is discussed further here. Because fluoride may have effects on fish at concentrations as low as 0.5 mg/l, and is a constituent associated with former site operations, DEQ requested that Tektronix further consider the significance of fluoride in surface water. Additional fluoride data was collected in Beaverton Creek and concentrations ranged from 0.32 to 0.53 mg/l. Based on this data, there does not appear to be significant site-related risks associated with fluoride since the measured concentrations of fluoride appear similar to upgradient background concentrations, and are within the range of uncertainty with respect to a threshold of effects. The remaining CPECs in soil and surface water were carried forward to the feasibility study. Cyanide was detected in both sediment and soil. Because no terrestrial or sediment ecological SLVs are available for this chemical it was carried forward as a CPEC. No additional evaluation of cyanide was performed in the ecological risk assessment. Cyanide has little toxicological data available to assess significance in soils, since it is best known as an aquatic toxicant and has not been extensively studied in the terrestrial environment. However, concentrations in the range of 1 to 5 mg/kg have been suggested as levels representative of a relatively low-level of contamination, as compared to the maximum soil concentration of mg/kg, measured in EA1 (Environmental Contaminants Encyclopedia, Entry on Cyanide, Roy Erwin Ed., July 1997). The maximum sediment concentration in Beaverton Creek (3.54 mg/kg) was not associated with any measurable toxicity (see Section ). Based on the foregoing considerations, DEQ considers the terrestrial ecological risk from cyanide in soil at EA1 to be acceptably low Sediment Toxicity Evaluation A summary of the analytical data for metals in Beaverton Creek compared to DEQ ecological screening level values (SLVs) for freshwater sediments, collected during the 2004 RI data collection effort, are shown in Table

20 Table 3-6 Summary of 2004 Analytical Data Relative to Sediment Screening Values Analyte a N Minimum Maximum Mean b SLV Background c ODEQ Cadmium 59 < Chromium Copper Lead Mercury 59 < Nickel Silver 59 < Zinc , Units in mg/kg -dry weight a -Arsenic was not analyzed in sediment as part of the Tektronix RI. b - Arithmetic mean of detected concentrations. c - DEQ 2002, Default background concentrations for metals. SLV - Screening Level Value for freshwater sediment Because concentrations of metals in Beaverton Creek sediment significantly exceeded DEQ ecological screening level values (see Table 3-6) additional investigation was planned to evaluate the potential significance of these exceedances. The objective of the investigation was to further consider toxicity and bioavailability of contaminants as a means to refine the scope of any remedial action. The sediment toxicity evaluation consisted of two primary, sequentially implemented elements of investigation: Additional sediment analytical chemistry, including both bulk sediment metals concentrations, measurement of acid-volatile sulfides (AVS) and simultaneously extractable metals (SEM) as metrics that could be related to the bioavailability, and hence potential for toxicity. Secondly, toxicity tests in were performed in a subset of these samples based on consideration of the potential for toxicity as measured by AVS-SEM, total metals and spatial representativeness throughout the relevant stretch of Beaverton Creek. Sediment samples for analytical chemistry were collected at 20 locations throughout the study reach, and two upgradient reference samples. Two toxicity tests, the 10-day mortality sediment toxicity test with the amphipod Hyalella azteca and the 10-day growth and mortality sediment toxicity test with the midge Chironomus dilutus, were performed on 13 surface sediment samples collected at a subset of 11 locations within the site and at the two upstream locations. Average bulk sediment concentrations measured in 2007 were similar to those measured in the 2004 sampling event (see Table 3-7) although the spread or range in values was narrower than those collected in Table 3-7 Summary of 2007 Analytical Data Analyte N Minimum Maximum Mean a Cadmium Chromium Copper Lead Mercury Nickel Silver Zinc Units in mg/kg -dry weight a - Arithmetic mean of detected concentrations by location. 3-10

21 According to US EPA guidance, the sum of the molar concentrations of SEM cadmium, copper, lead, nickel, silver, and zinc may be used as a predictor of potential toxicity. The EPA guidelines state that benthic organisms in freshwater sediments should be adequately protected if the sum of the molar concentrations of SEM cadmium, copper, lead, nickel, silver, and zinc is less than or equal to the molar concentration of AVS (i.e., SEM-AVS <1). As a second metric, the presence of organic carbon was considered along with AVS, and the SEM-AVS difference was normalized by the fraction of organic carbon (foc) in sediment. Again, according to US EPA guidance, any sediment for which the SEM-AVS difference normalized by the foc is less than 130 μmol/goc should pose low risk of adverse biological effects. For sediment for which the SEM-AVS difference normalized by the foc is greater than 3,000 μmol/goc, adverse biological effects resulting from cadmium, copper, lead, nickel, silver, and zinc may be expected. As measured by these evaluative criteria, the results from sediment indicated a low potential, but do not clearly rule out, potential for toxicity in most samples (see Table 3-8). Table 3-8 Sediment SEM and AVS as Predictors of Toxicity SampleID a SEM (umol/g) AVS (umol/g) SEM-AVS (umol/g) SEM-AVS/foc (umol/goc) SED SED SED-04A SED SED SED SED SED SED SED SED SED SED SED SED SED SED SED SED SED SED SED SED-18B SED Based on the results of toxicity testing, none of the sediment samples had an adverse effect on amphipods or midges based on the H. azteca mortality endpoint or C. dilutus growth endpoint. Based on the C. dilutus mortality endpoint, a few of the samples did show a weak response. Using regional and US EPA interpretive criteria, the results did not appear to be attributable to any of measure of metals in the sediments. In summary, the 2007 bulk sediment chemistry data were similar, on average to those collected in 2004, additional measures of bioavailability were collected and suggested an overall low potential for toxicity. 3-11

22 Toxicity testing indicated no toxicity that could be related to any measured sediment metal concentrations. Therefore, it was concluded that site sediments do not pose risks to benthic organisms or aquatic dependent wildlife and sediment remediation was deemed unnecessary. With respect to bank soils, and potential for erosion to be a significant source of metals to Beaverton Creek sediment, Tektronix provided additional interpretive information in February Existing sediment conditions reflect ongoing erosion and deposition occurring over many years, and bank soil concentrations were not substantially elevated over existing sediment concentrations. In light of the fact that existing sediment concentrations are protective for in-water receptors, and sediment concentrations generally are similar to bank soils, the available evidence indicates that bank soils do not pose unacceptable risks to in-water receptors by the erosion pathway. 3.3 IDENTIFICATION OF HOT SPOTS Hazardous substances that may have a significant adverse effect on beneficial uses of groundwater and hot spots of contamination in media other than water were identified during the Remedial Investigation as described in OAR (6) and (7). The criteria used to evaluate remedial alternatives for media other than groundwater or surface water must meet requirements for hot spots that are described in OAR (32)(b). Media other than groundwater or surface water for the Tektronix site EA1 include primarily Beaverton Creek bank soil. Criteria to determine whether remediation of hot spots is necessary are based on whether contamination presents an unacceptable risk to human or ecological receptors (1x10-4 level for carcinogens, 10 times the hazard index for non-carcinogens, or 10 times the acceptable risk level for individual or populations of ecological receptors), contamination is likely to migrate to create another hot spot or cannot be reliably contained. The criteria used to evaluate remedial alternatives for groundwater and surface water depend on whether or not a hot spot is present, as determined by a loss of current or reasonably likely future beneficial use of the water resource as described in OAR (9) and OAR (32)(a) Soil Hot Spots As described in Section 3.2.2, soils on site do not pose any unacceptable human health risks. Accordingly, no human health hot spots exist in soil. Ecological risks in soil, as described in Section 3.2.3, were based on exceedance of DEQ s screening level values (SLVs). No Threatened and Endangered Species were identified as receptors in the ecological risk assessment. In this case, preliminary ecological soil hot spots are identified by application of a 50-fold multiplier to the soil SLV. Based on this analysis, soil in the Beaverton Creek operational unit were identified as a hot spot for Chromium. However, the SLV on which this determination is based is 0.4 mg/kg for terrestrial invertebrates, and the corresponding preliminary hot spot value is below the estimate of background chromium of 27 mg/kg. Therefore, the estimate of background at 27 mg/kg is the preliminary hot spot criterion for the BCOU. Because the analysis of Beaverton Creek sediments demonstrated low potential for bioavailability of metals to aquatic organisms, including chromium, and because it is presumed that the source of metals to both Beaverton Creek and bank soils is the same, it may be reasonable to infer that bioavailability of chromium to terrestrial receptors may also be low, and that higher levels in soil may not produce unacceptable risk. Additional evaluation of this soil preliminary hot spot will be considered in the remedial design phase Groundwater Hot Spots The human health risk assessment (see Table 12) identified unacceptable risks in surface water and groundwater for a group of VOCs. Among these TCE exceeded hot spot levels based on the vapor intrusion to indoor air pathway. Potential hot spots exist in shallow groundwater in several areas across 3-12

23 the site. These areas are approximately delineated in the Feasibility Study, dated July 17, 2008, Landau Associates and are shown on Figures 3-4 and INTERIM REMEDIAL ACTIONS Interim remedial actions have been completed at the site and include a variety of actions for building closure and removal, and soil and groundwater treatment and containment. Final closure of all RCRA units will occur when the Cleanup Order is satisfied and all closure conditions under the Permit have been satisfied Building 10/12 Building 10 was constructed in 1977 and was the storage location for fresh and spent chemicals. This building was closed under RCRA regulations and oversight in 2004 and the building and all related piping, sumps tanks and vaults have been demolished and removed. Groundwater contamination present beneath the building area will be address in this final remedial action. Building 12 was constructed in 1980 to store containerized waste. This building was closed under RCRA regulations and oversight in 1997 and the building and all related structures have been removed. During the closure process sampling was conducted on the inside of the building, and also for soil and groundwater beneath the building after demolition. Contaminated soil exceeding risk-based criteria in the building sump area were removed as part of the closure. An air sparging and vapor extraction treatment system was installed and operated from 1997 to 2004 to address soil and groundwater contamination. The system reduced concentrations of contaminants in soil and groundwater to below applicable risk-based concentrations. DEQ approved Tektronix request to cease treatment and the system was removed in Building 40 Facility and Surface Impoundments Building 42 was originally built in 1962 to manage fresh and waste chemicals and to treat waste waters and was replaced in 1982 with Building 40 which included the IWWTF to treat plating and bath stream wastes. The RCRA permitted facilities related to Building 40 and the IWWTF included tanks, surface impoundments and mechanical equipment for managing accumulated sludge. Surface impoundments were RCRA closed in place, including placement of a RCRA cap, in 1988 with certification provided by DEQ in The RCRA permitted tanks and sludge management equipment were RCRA closed between 2000 and Partial closure of Building 40 was approved by DEQ then it was demolished in accordance with an approved closure plan. Closure activities were documented in RCRA Closure Report, Tektronix Beaverton Campus, Building 40, April 2003, URS. The surface impoundments and RCRA cap were excavated and removed in 2005 per a DEQ-approved work plan; the work conducted was documented in Final Interim Remedial Action Measures Report, August 8, 2006, Kennedy Jenks. Soil and groundwater beneath the Building 40 and IWWTF area have been investigated as part of the remedial investigation for EA1. A groundwater containment and treatment system, installed prior to removal of Building 40 and the surface impoundments, has been preserved through the interim action, continues to operate, and will be incorporated into the final remedy selected for EA West Park Parcel Groundwater Building 40 IWWTF sludge applied to the ground from 1970 to 1980 released contamination to soil and groundwater at the West Park parcel. Based on results of a groundwater investigation, groundwater was remediated with a groundwater pump and treat system was installed in 1989 and continued to operate until Concentrations of TCE were reduced by 2 or 3 orders of magnitude primarily through in situ degradation. In 1996 the treatment interim action was modified to monitored natural attenuation (MNA). Performance monitoring for the MNA was conducted from 1996 through 2007 when a NFA was issued by DEQ for deep groundwater and all groundwater monitoring ceased at the site. Groundwater 3-13

24 monitoring wells were decommissioned in June 2007 per Oregon Department of Water Resources requirements. Beaverton Creek sediments and bank soil at the West Park parcel are the remaining areas of concern to be addressed through this final remedy Building 02 Gas Injection Leakage from spent chemical storage at Building 2 resulted in release of contamination to soil and groundwater at this parcel. A groundwater extraction and treatment system was installed at this parcel in 1990 and continues to operate to reduce VOC concentrations in groundwater and contain the groundwater plume. A pilot study was conducted in 2004 and 2005 pursuant to a DEQ-approved work plan to evaluate the effectiveness of in situ bioremediation through gas injection. Installation of the gas injection system included installation of two gas injection wells and construction of an injection system for delivery of a mixture of propane and oxygen into the subsurface to stimulate aerobic co-metabolic bioremediation of the chlorinated VOCs in groundwater. In December 2005 it was determined that this is not a viable technology for the low permeability Willamette Silt and as a result the system was decommissioned with DEQ approval Groundwater Extraction at Buildings 40, 16 and 02 A groundwater extraction and treatment system currently operates to address VOC contaminated groundwater in the former Building 40, Building 16 and Building 2 areas. The systems extract contaminated groundwater through extraction wells and the extracted groundwater is treated above ground using air sparging technology. In the Building 40 area the extraction system also includes an impoundment under drain system using collection sumps (modified during impoundment removal) to drain contaminated shallow groundwater from the former impoundment areas. In the area between former Building 40 and Building 16, cutoff collars have been installed to prevent horizontal movement of contaminated groundwater through utility backfill. These groundwater extraction systems have been demonstrated to be effective for containment of the groundwater contaminant plumes in these three areas. 3-14

25 4 PEER REVIEW SUMMARY Technical documents produced during the investigation of the Tektronix Evaluation Area 1 site have been reviewed by a technical team at DEQ. The team consists of the project manager and hydrogeologist, an engineer, and a toxicologist. The team unanimously supports the selected remedial action as documented on the staff report sign off sheet which is listed in the Administrative Record in Section

26 5 DESCRIPTION OF REMEDIAL ACTION OPTIONS 5.1 REMEDIAL ACTION OBJECTIVES The standards for a protective cleanup are defined in the Oregon Revised Statute (ORS) and Oregon Administrative Rule (OAR). ORS states in part that any removal or remedial action shall attain a level of cleanup that assures protection of present and future public health, safety and welfare and of the environment. Acceptable risk levels as defined in OAR (1) through (6) were selected, and remedial action objectives were developed, based on the identified land uses, beneficial water uses, exposure pathways and the risk assessment Remedial Action Objectives Site-specific remedial action objectives (RAOs) were developed for soil and groundwater for the purpose of achieving protection of human health, ecological receptors, and beneficial uses, as required by OAR The RAOs for the site are as follows: RAO 1. Prevent human exposure to TCE in shallow groundwater through dermal contact for excavation workers that would result in unacceptable excess lifetime cancer risk greater than 1x10-6 and HI greater than 1. RAO 2. Prevent human exposure to TCE in surface water through dermal contact and inhalation for recreational users that would result in an unacceptable risk. RAO 3. Prevent human exposure to TCE in indoor/outdoor air through inhalation that would result in an unacceptable risk. RAO 4. Prevent ecological receptor exposure to metals in creek bank soil that would result in unacceptable risk for populations of non-t&e species. RAO 5. Prevent migration of VOCs in shallow groundwater into surface water or indoor/outdoor air at concentrations that exceed acceptable risk levels. RAO 6. Remediate hot spots of contamination in groundwater, and bank soil by reducing their concentration, volume or mobility to be protective of human and ecological receptors as specified in OAR (4) Risk Based Cleanup Levels and Hot Spot Concentrations No site-specific acceptable risk levels were calculated for the site. Rather, default values are used from DEQ s guidance, including Risk-Based Decision Making for Petroleum Contaminated Sites (RBDM), DEQ, Acceptable risk levels and hot spot criteria are summarized in Table 5-1 below. 5-1

27 Table 5-1 RBCs and Hot Spot Criteria COCs Groundwater RBC (ug/l) Groundwater Hot Spot (ug/l) Bank Soil (mg/kg) Terrestrial SLV Hot Spot Chemicals of Human Health Concern Trichloroethene (TCE) ,000 NA NA Chemicals of Ecological Concern Cadmium NA NA Chromium NA NA 27 a 27 a Copper NA NA 50 2,500 Lead NA NA 17 b 800 Mercury NA NA Silver NA NA Zinc NA NA 96 b 2,500 a - Estimate of background concentration in soil. Because the lowest screening value is 0.4 mg/kg, the estimated background concentration exceeds hotspot (see Section 5.2.2) b - Estimate of background concentration in soil. Groundwater hot spot for TCE is 100 x RBC. Terrestrial ecological hotspot is 50 x SLV. 5.2 ESTIMATED VOLUME OF CONTAMINATED MEDIA This section provides estimated areas and volumes of contaminated groundwater and bank soil that exceed risk-based criteria and/or hot spot criteria Groundwater TCE is identified as contributing the most risk of exposure to groundwater for the vapor intrusion and excavation worker pathways. Source areas where the TCE concentration exceeds the vapor intrusion pathway criterion of 110 ug/l are shown on Figures 3-2 and 3-3 for the west and east portions of EA1, respectively. Four source areas are present in the west area (Figure 3-2) and range from 2,500 to 6,500 sf. Two source areas are present in the east area (Figure 3-3); their areas are not calculated because their concentrations are below the effective treatment threshold concentration discussed in later section The total surface area of source zones in west EA1 where contaminated shallow groundwater exceeds the vapor intrusion criterion is equal to about 84,000 square feet (sf). The combined volume of soil and groundwater that exceeds the vapor intrusion criterion in the shallow, intermediate and deep zones is about 56,000 cubic yards (cy). The 84,000 sf area also approximately represents the area exceeding the excavation worker criterion of 130 ug/l for TCE. This assumes a shallow zone saturated thickness of 18 feet, with 5 feet of saturated aquifer above the typical 15-foot excavation depth, for a total of about 15,500 cy. There is an estimated 785,400 to 2,827,000 gallons of contaminated groundwater, using an estimated porosity of 0.25, for the excavation worker and vapor intrusion pathways, respectively. 5-2

28 5.2.2 Bank Soil Surface soil along Beaverton Creek banks contains metals concentrations that exceed screening level values for terrestrial receptors. The estimated area where soil contamination exceeds RBCs is about 100,000 sf, and the estimated volume of this contaminated soil is 9,200 cy based upon an average depth of contaminated soil of 2.5 feet. Of the metals exceeding ecological criteria, only chromium exceeds hotspot levels. However, the chromium ecological screening value, and corresponding hotspot value are relatively uncertain. Because the bank soil exceedances are based on screening level criteria, and because the area exceeding these criteria needs further definition, additional sampling is proposed during remedy design to meet the objectives of further delineating the impacted area, and evaluating the significance of these screening level exceedances. Based on the results of this additional characterization, the need and scope of the proposed remediation for bank soils will be reconsidered Indoor/Outdoor Air TCE contributes most of the risk for the migration from shallow groundwater to indoor and outdoor air pathways. Elevated concentrations of TCE have been detected only in Building 38. The footprint of the Building 38 foundation is about 23,000 sf. Future buildings are not planned at this time therefore area calculations have not been made. No volume calculations have been made for outdoor air. 5.3 APPLICABLE LAWS AND STANDARDS Remedial alternative development for the Tektronix facility considered the following applicable or relevant and appropriate requirements. The site is located in unincorporated Washington County therefore there will be no permitting requirements for the City of Beaverton Oregon Air Pollution Control Rules (OAR ) These rules specify emission limits and operating and reporting requirements for stationary air pollution sources and may apply to the site remedial actions Oregon Hazardous Waste Management Act (ORS 466) This act and its implementing administrative regulations (OAR et seq.) govern the generation, transportation, treatment, storage, and disposal of hazardous wastes. These rules may have applicability at the site if remedial actions generate characteristic or listed hazardous wastes (including environmental media such as contaminated soil and/or groundwater). The act incorporates the requirements of the federal Resource Conservation and Recovery Act (RCRA) program Oregon Solid Waste Management (ORS 459 and OAR and ) This statute and implementing rules govern the management of solid wastes, including the permitting of disposal sites, and are applicable to the off-site management and disposal of the contaminated bank soil. Off-site disposal of the excavated contaminated bank soil will comply with the applicable solid waste regulations Oregon Underground Injection Rules (OAR ) These rules apply to the injection of any fluids into groundwater, including re-injection of extracted groundwater such as for enhancing biodegradation. Injection of fluids requires registration of the site Oregon Water Quality Standards (ORS 468B and OAR ) These standards protect aquatic life and public health, and are applicable to the Tektronix site for any discharges to Beaverton Creek from shallow groundwater or stormwater runoff. 5-3

29 5.3.6 Oregon Water Pollution Control Act (ORS 468B and OAR ) This act and the implementing administrative rules govern discharge of pollutants to surface waters. The act incorporates the federal Clean Water Act (CWA) programs, including the NPDES permitting system Oregon Occupational Safety and Health Code (OAR 347) These codes, analogous to the federal Occupational Safety and Health Administration codes, contain health and safety requirements that must be met during implementation of any remedial action. These standards are intended to protect construction and utility workers at the site Oregon Water Resource Department Regulations (OAR 690) These regulations apply to the appropriation and use of groundwater, water rights transfers, and well construction and abandonment standards Archeological and Historical Preservation Act (16 USCA 469a-1) This act may be applicable to the site for any archeological or historical materials found during remedy implementation excavation or construction Oregon Noise Control Rules (OAR ) These rules may be applicable to remedial activities at the site. 5.4 REMEDIAL ALTERNATIVES DEVELOPMENT General response actions and remedial technologies for groundwater, indoor/outdoor air, shallow soil (Beaverton Creek banks), and surface water were screened in Tables 4-2 through 4-5 of the FS. The general response actions for these media included: no action, institutional controls, engineering controls, containment, treatment, and removal actions. Several remedial technologies were evaluated for each general response action. Viable response actions and technologies that can meet the RAOs were assembled into remedial action alternatives. Remedial alternatives developed for groundwater, indoor air and shallow soil are summarized in Table DESCRIPTION OF ALTERNATIVES Groundwater Alternatives Four remedial alternatives have been developed and include: Alternative 1 No Action, Alternative 2 Groundwater Extraction and Treatment, Alternative 3 Electrical Resistance Heating, and Alternative 4 Enhanced Reductive Dechlorination. These alternatives and their common elements are discussed below Common Elements Except for Alternative 1 No Action, common remedial elements are: institutional controls, engineering controls, monitored natural attenuation, and long-term groundwater and surface water monitoring. These common elements are discussed below and will not be repeated in the descriptions that follow of Alternatives 2 through 4. Institutional Controls. Institutional controls will consist of use restrictions for construction of new buildings or excavation in areas where TCE concentrations in soil and groundwater exceed RBCs for indoor air and dermal contact for excavation workers. Use restrictions will be incorporated into an Easement and Equitable Servitudes (EES) to be developed and filed during remedial design. The EES will contain use restrictions and will require that future development consider proper design for new buildings protective for the indoor air pathway and excavations be conducted pursuant to a soil management plan. The soil management plan will provide 5-4

30 protocols for handling and management of potentially contaminated soil and will be developed during remedial design. The cost for institutional controls is included in the total cost of each of Alternatives 2 through 4. Engineering Controls. Engineering controls identified as contingency measures will consist of adjustment of the HVAC system to maintain a positive pressure and installation of a vapor barrier coating on the bottom level floor of building 38. These engineering control contingency measures will be implemented if the building will be occupied before groundwater remediation is complete or if the completed groundwater remedy fails to reduce indoor air concentrations to below occupational indoor air RBCs. A first step will be to apply a floor sealant that should significantly reduce or eliminate intrusion of VOCs from the subsurface into the building. If the floor sealant is not effective in maintaining indoor air TCE concentrations below the 0.1 ug/m 3 RBC then adjustments to the HVAC system would be made to produce a net positive pressure inside the building so that there is always sufficient air flow out of the building to prevent infiltration of VOC vapor emanating from shallow groundwater beneath the building. The total cost for HVAC and floor sealant actions is $239,000. Monitored Natural Attenuation. Monitored natural attenuation (MNA) is proposed to be applied to areas that exceed groundwater RBCs but are outside of source areas where NAPL may be present. Interim remedial measures taken at the West Park Parcel between 1996 and 2006 document that reductive dechlorination of PCE and TCE through anaerobic biodegradation does occur within the uppermost Willamette Silt and is effective in reducing VOC concentrations to meet RBCs. The cost of MNA is included in the total cost of each of Alternatives 2 through 4. Groundwater, Surface Water and Indoor Air Monitoring. Perfomance monitoring of the implemented groundwater remedy would be conducted for groundwater in the leading edge and center of VOC plumes to evaluate plume migration and concentration trends over time, and in surface water in Beaverton Creek in the area and downstream of groundwater discharge. Groundwater monitoring will be conducted throughout the treatment period until RAOs have been achieved. Indoor air for Building 38 would be monitored periodically to determine the effectiveness of engineering controls then during operation of contingency measures if implemented. A Remedy Performance Monitoring Plan will be developed during remedial design that will provide details and schedules for groundwater, surface water and indoor air monitoring. Monitoring reports will be submitted according to the schedule in the approved performance monitoring plan during the course of the remedial action. The cost of long-term groundwater and surface water monitoring is included in the total cost of each of Alternatives 2 through Alternative 1: No Action No remedial action or monitoring would occur to address contamination in groundwater except to terminate operation of the existing IRAM systems at the site. The No Action alternative serves as a baseline for comparison of other potential remedial alternatives. Alternative 1 would not have an associated cost as no remedial actions are proposed Alternative 2: Groundwater Extraction and Treatment In addition to the common remedial elements this alternative would achieve groundwater RAOs through groundwater extraction and treatment of the contaminant source areas. Contaminated groundwater outside of source areas would be treated with MNA. The groundwater extraction system would be an expansion of the existing IRAM systems to add additional wells sufficient to establish hydraulic containment. Six new extraction wells are proposed: one at Building 38, one near Building 40, two in the area of the former unlined ponds, and two adjacent to Beaverton Creek. These six new wells would be operated along with the existing 6 extraction wells and two stormwater pipeline cutoff collars. The specific location of new extraction wells would be determined during remedial design. 5-5

31 For the purpose of remedial alternative development and cost evaluation, TCE source areas are defined as those areas where TCE concentrations in groundwater exceed 10,000 ug/l, which is also a hot spot for the vapor intrusion pathway. This concentration is approximately equal to one percent of the solubility limit for TCE in groundwater denoting the potential presence of NAPL in the subsurface. Treatment areas for remedial action are those areas where TCE concentrations in groundwater exceed 1,000 ug/l, which provides a conservative treatment margin around potential source/napl areas. The new and existing extraction wells and cutoff collars are expected to operate for at least 30 years before the concentration of TCE in groundwater is reduced to below the 1,000 ug/l treatment area threshold. Once this threshold is reached, then groundwater extraction would cease and groundwater would then be treated using MNA to achieve the groundwater cleanup RAO. Areas where TCE in groundwater exceeds 1,000 ug/l, but is below the source area threshold of 10,000 ug/l, are proposed to be treated using MNA. Past operation of the groundwater extraction IRAM systems indicates that at least one extraction and one monitoring well will need to be replaced annually as a result of silt entrainment. Treatment of extracted groundwater would use an on-site air-sparging treatment system that has the capacity to treat the existing and new proposed extraction wells. Treated groundwater would be discharged under the existing NPDES permit. The existing electrical control system will need to be expanded to provide power to the additional 6 extraction wells. The total cost for Alternative 2 is estimated to be $4,039,000 which includes work specific to Alternative 2 ($3,800,000; see Table 5-4) plus the cost of engineering controls ($239,000) Alternative 3: Electrical Resistance Heating This alternative would achieve groundwater RAOs through thermal treatment of contaminated soil and groundwater in treatment areas using electrical resistance heating (ERH; see Figures 3-2 and 3-3). ERH will involve installation of electrodes into the treatment areas and passing electrical current through the subsurface until groundwater reaches the boiling point at about 100 C. Electrodes would be co-located with vapor recovery wells for full recovery of vapors and steam. Contaminant vapors and steam would go to a steam condenser where they will be separated. The water condensate would be discharged to the sanitary sewer and vapors would be treated to remove or destroy the contaminants. Thermocouples would be installed to monitor the uniformity of temperature throughout the treatment area. A mass removal efficiency of at least 95% is anticipated. Approximately four years are expected for design, installation and operation of the ERH systems. During the estimated 2-year design period, the existing groundwater extraction IRAM will continue to operate. If a pilot test is conducted in one of the treatment areas prior to full scale operation, an additional one to two years would be needed. Once concentrations of TCE in groundwater are reduced to below the 1,000 ug/l treatment threshold (presented in the previous section as a definition for treatment areas) then MNA will be used to continue to treat groundwater to achieve the groundwater cleanup RAOs. MNA will be implemented in the Building 10 area where groundwater concentrations are above the 1,000 ug/l treatment area concentration but below the 10,000 ug/l source/napl area concentration. It is anticipated that MNA can achieve the cleanup levels for groundwater in about 10 years for a total treatment time of 12 to 14 years. Thermal treatment may affect existing extraction and monitoring wells in the treatment areas. Therefore, existing wells will be abandoned and new long-term monitoring wells will be installed after completion of the ERH portion of Alternative 3 remedy implementation. All wells will be abandoned at the end of treatment. The total cost for Alternative 3 is estimated to be $3,059,000 which includes the work specific to Alternative 3 ($2,820,000; see Table 5-5) plus the cost of engineering controls ($239,000). 5-6

32 Alternative 4: Enhanced Reductive Dechlorination This alternative will achieve groundwater RAOs through anaerobic bioremediation of contaminated groundwater in contaminant source/napl areas. The process of enhanced reductive dechlorination (ERD) will be used to create strongly reducing conditions in the subsurface to promote biological dechlorination through the sequence of parent and daughter products: PCE to TCE to 1,2-DCE to vinyl chloride to ethane. A combination of vegetable oil and sodium lactate is proposed to be injected into the subsurface using push probe technology in two sequential injections. This combination of electron donors is expected to accelerate the onset of methanogenic conditions and extend the time in which reducing conditions and residual electron donors are available. Approximately 2 years are expected for design of the ERD remedy with implementation (donor injection) to occur at the end of the 2-year design period. The existing groundwater extraction IRAM will continue to operate through the 2-year design period and for two years after donor injections. MNA will be utilized in the Building 10 area where groundwater concentrations are above the 1,000 ug/l treatment area concentration but below the 10,000 ug/l source/napl area concentration. Once TCE concentrations in groundwater are reduced to below the 1,000 ug/l treatment threshold then MNA will be used to achieve groundwater RAOs. The combination of ERD and MNA is estimated to achieve groundwater RAOs in about 30 years. Extraction and monitoring wells will be abandoned at the end of treatment. The total cost for Alternative 4 is estimated to be $2,809,000 which includes the work specific to Alternative 4 ($2,570,000; see Table 5-6) plus the cost of engineering controls ($239,000) Shallow Soil Alternatives Three remedial alternatives have been developed and include: Alternative 1 No Action, Alternative 2 Bank Soil Capping, and Alternative 3 Bank Soil Excavation. These alternatives and their common elements are discussed below Alternative 1: No Action This alternative would take no action to address contaminated shallow soil along the banks of Beaverton Creek Alternative 2: Bank Soil Capping This alternative would achieve bank soil RAOs by placement of a cap over Beaverton Creek shallow bank soil containing contaminants at concentrations that exceed ecological RBCs. The cap would consist of a permeable synthetic geotextile liner covered with a 1-foot thick layer of clean imported soil. The soil layer would be planted with grasses and other shallow-rooted plants to establish a root zone to prevent erosion. The textile fabric would be selected to withstand tearing and burrowing by animals. The areas identified for capping are shown on Figure 5-1. Annual inspection and maintenance would be performed to maintain the integrity of the bank soil cap. The total cost of Alternative 2 Bank Soil Capping is $540,000 based on inspection and maintenance for a 30-year period (see Table 5-7) Alternative 3: Bank Soil Excavation This alternative would achieve bank soil RAOs through excavation of bank soil containing contaminants at concentrations that exceed ecological RBCs. The areas identified for excavation are shown on Figure 5-1. After bank soil excavation, confirmation sampling would be conducted to determine whether bank soil RBCs have been met. No placement of replacement soil is proposed. Contaminated bank soil would be disposed off-site. The total cost for Alternative 2 Bank Soil Excavation is $920,000 (see Table 5-8). 5-7

33 5.5.3 Periodic Monitoring, Review and Contingency Plan There are a number of uncertainties at the site that make it difficult to predict the long-term effectiveness of any of the remedial action alternatives described above including: Heterogeneity in the subsurface and in material parameters, Potential changes in future groundwater or surface water beneficial uses, Potential changes in future land use zoning, Changes in community concerns regarding remedial actions at the site, Long-term performance of the groundwater or soil remedies, or Effectiveness of the selected remedial actions for site conditions. Because of these uncertainties, a periodic monitoring review and contingency plan will be developed that will evaluate the performance of the remedy, and any changes that may affect the ability of the remedy to meet the RAOs. The objective of the periodic monitoring, review and contingency plan will be to maintain the overall protectiveness of the selected remedy by establishing a series of decision criteria and related response actions for each potential area of uncertainty identified above, and the RAOs listed in Section of this document. The first component of the contingency plan will be a review of both performance monitoring data and local land and water uses. If monitoring data exceed site RBCs in selected monitoring wells or at surface water compliance points, an expanded monitoring program will be initiated. If the supplemental groundwater and surface water monitoring data indicates that the RAOs are not being met, then additional remedial actions will be evaluated to ensure that human health and the environment are protected. If air monitoring data for Building 38 exceed site RBCs for indoor air after installation of engineering controls described in Section , then the contingency measure of installation of a soil vapor extraction (SVE) system at Building 38 will be implemented. The estimated cost for the SVE system is $163,000 and includes installation and operation and maintenance for a 5-year period. 5-8

34 6 EVALUATION AND COMPARISON OF REMEDIAL ACTION ALTERNATIVES 6.1 EVALUATION CRITERIA The criteria used to evaluate the remedial action alternatives described in Section 5 are defined in OAR , and establish a two-step approach to evaluate and select a remedial action. The first step evaluates whether a remedial action is protective; if not, the alternative is unacceptable and the second step is not required. In the second step, the remedial alternatives considered protective are evaluated and compared with each other using five balancing factors. The five balancing factors are 1) effectiveness in achieving protection, 2) long-term reliability, 3) implementability, 4) implementation risk, and 5) reasonableness of cost. 6.2 PROTECTIVENESS The protectiveness of a given remedial action is evaluated by comparing actual or estimated future COC concentrations to RBCs described in Section of this document. The pathways or beneficial uses for which the anticipated maximum concentration of a COC exceeds the RBCs for EA1 of the Tektronix site are: Direct contact by excavation worker with VOCs in shallow groundwater Inhalation of VOC vapors emanating from shallow groundwater into indoor air Direct contact by terrestrial receptors with shallow soil in Beaverton Creek banks for chromium These are the pathways and beneficial uses that will be directly evaluated to establish if a given remedial alternative is protective. OAR states that protectiveness may be achieved by any of the following methods: Treatment Excavation and off-site disposal Engineering controls Institutional controls Any other method of protection A combination of the above With the exception of hot spots, there is no preference for any one of the above methods for achieving protectiveness. Where a hot spot has been identified, OAR (4) establishes a preference for treatment to the extent feasible, including a higher threshold for evaluating the reasonableness of costs for treatment Groundwater Alternative 1: No Action Alternative 1 would turn off existing IRM systems and then would take no further action to minimize or eliminate potential human exposure to groundwater, by reducing concentration or mass of COCs, controlling COC plumes in groundwater, or using engineering or institutional controls. The potential would still exist for future exposure of occupational workers to be exposed to contaminated soil or groundwater or vapors from groundwater that may invade existing or future buildings. Therefore, groundwater Alternative 1 is not protective and is not evaluated further Alternative 2: Groundwater Extraction and Treatment Alternative 2 would treat contaminated groundwater through extraction and treatment ex-situ using an existing air-sparging treatment system. Source areas with concentrations greater than1,000 ug/l will be treated using groundwater extraction. Areas outside of source areas will be treated with MNA which has been shown to be effective for the soil type present at the site. Once concentrations within source areas are reduced to 1,000 ug/l the source areas would be further treated using MNA. Short term exposure to 6-1

35 contaminated groundwater would be managed using institutional and engineering controls. These actions will eliminate direct access to contaminated groundwater and reduce concentrations of COCs in groundwater to achieve the RAOs for direct contact and migration of contaminant vapor to indoor air. Alternative 2 is considered protective of human receptors and is carried forward for further evaluation Alternative 3: Electrical Resistance Heating Alternative 3 would treat contaminated groundwater through thermal treatment of source areas where COCs are present above 1,000 ug/l. Subsurface soil and groundwater within source areas would be heated to about 100ºC and resultant vapors would be captured, treated and disposed. Once source area COC concentrations have been reduced to below 1,000 ug/l then they would be further treated using MNA along with all other areas outside of source areas where COCs exceed RBCs. Short term exposure to contaminated groundwater would be managed using institutional and engineering controls. These actions will eliminate direct access to contaminated groundwater and reduce concentrations of COCs in groundwater to achieve the RAOs for direct contact and migration of contaminant vapor to indoor air. Alternative 3 is considered protective of human receptors and is carried forward for further evaluation Alternative 4: Enhanced Reductive Dechlorination Alternative 4 would treat contaminated groundwater through anaerobic bioremediation. Natural dechlorination of COCs will be enhanced by injecting a substrate into the subsurface in source areas where COC concentrations exceed 1,000 ug/l. After concentrations of COCs are reduced below 1,000 ug/l, contaminated groundwater in the source areas will be further treated using MNA, along with all other treatment areas where VOCs exceed RBCs. Short term direct contact exposure would be managed using institutional and engineering controls. These actions will eliminate direct access to contaminated groundwater and reduce concentrations of COCs in groundwater to achieve the RAOs for direct contact and migration of contaminant vapor to indoor air. Alternative 4 is considered protective of human receptors and will be carried forward for further evaluation Shallow Bank Soil Alternative 1: No Action Alternative 1 would take no action with regard to metals contamination in shallow bank soil in Beaverton Creek. Soil with CPOCs above RBCs would remain in place and accessible for future exposure by terrestrial receptors. Therefore, soil Alternative 1 is not protective and is not considered further Alternative 2: Bank Soil Capping Alternative 2 would achieve RAOs for bank soil by capping areas of contamination above RBCs with a permeable geotextile liner and soil cover. Shallow-rooted plants such as grasses would be planted on the soil cover to establish a root-zone to prevent erosion of the cap. Capping of bank soil would eliminate direct contact with contaminated soil by terrestrial receptors and be designed to withstand seepage pressures, tearing through burrowing and erosion. Alternative 2 is considered protective of terrestrial receptors and is carried forward for further evaluation Alternative 3: Bank Soil Excavation Alternative 3 would achieve RAOs for bank soil by excavating shallow soil containing CPOCs above RBCs and disposing offsite. Excavation and disposal of contaminated bank soil would eliminate direct contact with contaminated soil by terrestrial receptors. Alternative 3 is considered protective of terrestrial receptors and is carried forward for further evaluation. 6-2

36 6.3 BALANCING FACTORS The remedial alternatives determined to be protective, Alternatives 4 through 4 for groundwater and Alternatives 2 and 3 for shallow soil, are evaluated and compared against the following balancing factors defined in OAR (3): Effectiveness in achieving protection. The evaluation of this factor includes the following components: Magnitude of the residual risk from untreated waste or treatment residuals, without considering risk reduction achieved through onsite management of exposure pathways (e.g., engineering and institutional controls). The characteristics of the residuals are considered to the degree that they remain hazardous, taking into account their volume, toxicity, mobility, propensity to bioaccumulate, and propensity to degrade. Adequacy of any engineering and institutional controls necessary to manage residual risks. The extent to which the remedial action restores or protects existing or reasonably likely future beneficial uses of water. Adequacy of treatment technologies in meeting treatment objectives. The time until remedial action objectives are achieved. Long-term reliability. The following components are considered when evaluating this factor, as appropriate: The reliability of treatment technologies in meeting treatment objectives. The reliability of engineering and institutional controls needed to manage residual risks taking into consideration the characteristics of the hazardous substances being managed, the ability to prevent migration and manage risk, and the effectiveness and enforceability over time of the controls. The nature and degree of uncertainties associated with any necessary long-term management (e.g., operations, maintenance, monitoring). Implementability. This factor includes the following components: Practical, technical, legal difficulties and unknowns associated with the construction and implementation of the technologies, engineering controls, and/or institutional controls, including the potential for scheduling delays. The ability to monitor the effectiveness of the remedy. Consistency with regulatory requirements, activities needed to coordinate with and obtain necessary approvals and permits from other governmental bodies. Availability of necessary services, materials, equipment, and specialists, including the availability of adequate treatment and disposal services. Implementation Risk. This factor includes evaluation of the potential risks and the effectiveness and reliability of protective measures related to implementation of the remedial action, including the following receptors: the community, workers involved in implementing the remedial action, and the environment; and the time until the remedial action is complete. Reasonableness of Cost. This factor assesses the reasonableness of the capital, O&M, and periodic review costs for each remedial alternative; the net present value of the preceding; and if a hot spot has been identified at this site, the degree to which the cost is proportionate to the benefits to human health and the environment created through treatment of the hot spot. In general, the least expensive remedial action is preferred unless the additional cost of a more expensive corrective action is justified by proportionately greater benefits to one or more of the other balancing factors. For sites with hot spots, the costs of remedial actions must be evaluated to determine the degree to which they are proportionate to the benefits created through restoration or protection of beneficial uses of water. A higher threshold will be used for evaluating the reasonableness of costs for treatment of hot spots than for remediation of areas other than hot spots. The sensitivity and uncertainty of the costs are also considered. 6-3

37 6.4 REMEDIATION OF HOT SPOTS The evaluation of remedial action alternatives, with respect to the remediation of hot spots of contamination in media other than water, considers the treatment or excavation and off-site disposal at an authorized disposal facility or the combination of treatment or excavation to the extent such measures are feasible based on the criteria in OAR (7), and the balancing factors set forth in OAR (3) and previously described. For hot spots of contamination in water, the evaluation of feasibility of treatment is based on criteria in OAR (5) and the balancing factors set forth in OAR (3) and described above. 6.5 COMPARATIVE ANALYSIS OF BALANCING FACTORS This section evaluates each of the remedial action alternatives that met the protectiveness criteria against the balancing factors described in Section 6.3 and compares the alternatives against each other. This comparative analysis is presented below for the groundwater alternatives, and for the shallow bank soil alternatives. The sections below summarize the major conclusions of this comparison and provide additional discussion for differentiating issues at this site Groundwater Alternatives 2 through Effectiveness Alternative 3 using ERH is considered the most effective of the three alternatives in achieving RAOs by treating hot spots and areas of contamination above RBCs. Alternative 4 using ERD is considered less effective than Alternative 3, and Alternative 2 using Groundwater Extraction and Treatment is considered less effective than Alternative 4. Alternative 3 is considered most effective because ERH technology is known to be effective for high concentration source areas in low permeability materials such as the Willamette Silt and Hillsboro Formation. ERH is expected to reduce VOC concentration in source areas below 1,000 ug/l within 2 years, and in combination with MNA achieve RAOs within about 10 years. Alternative 4 is less effective because of the uncertainty in ability to inject and distribute the electron donor throughout the contaminated area even though low viscosity liquids are proposed. ERD in combination with MNA is expected to achieve RAOs within about 30 years. Alternative 2 is less effective than Alternative 4 because of the low permeability of source area soil. Groundwater extraction and treatment would require at least 30 years to reduce VOC concentrations to below 1,000 ug/l before MNA would be implemented to achieve RAOs, a much longer time than Alternatives 3 and Long-term Reliability Alternative 3 is considered to have the highest long-term reliability, followed by lower long-term reliability Alternative 4, then Alternative 2. Alternative 3 is considered most reliable because it will remove all source/napl areas and the residual heat from this technology will enhance biodegradation of COCs in and adjacent to the treated source areas. Alternative 4 is considered of lower long-term reliability because the continued breakdown of COCs in source areas must rely upon adequate initial distribution of injected donor material, persistence of the donor material over time, and potential reinjection of additional donor material. Alternative 2 is considered to have the least long-term reliability because of the length of time required to achieve RAOs in the face of the need for continued maintenance of a pumping network and treatment system and potentially changing land and water use conditions in the unforeseeable future Implementability Alternatives 2 and 3 are both considered to be readily implementable. Alternative 4 is considered to have a lower ease of implementation because the uncertainty in ability to effectively inject donor material throughout the treatment area which would need to be established by conducting a pilot study. 6-4

38 Implementation Risk The implementation risk is considered to be relatively equal between Alternatives 2 and 4 and slightly higher for Alternative 3. Alternative 2 may result in accidental leaks or spills to the surface or into surface water of extracted groundwater with high concentrations of COCs resulting in the potential for increased direct contact exposure by workers or ecological receptors. Alternative 4 may result in generation of more toxic end products of degradation of TCE and release of those more toxic substances into groundwater discharging to surface water or migrating into indoor air. Alternative 3 presents a higher risk of implementation to workers during application of the ERH technology because of the use of high voltage electrical power and the potential for releases at the surface of steam or hot waters from the treatment zone. There are also potential risks of migration of vapors into indoor air if the vapor extraction system is not operated properly Reasonableness of Cost The relative costs for the three groundwater alternatives are Alternative 4 with the least cost, Alternative 3 with a higher estimated cost and Alternative 2 with the highest estimated cost. However, Alternative 3 is considered to be the most cost-reasonable because of the expected high effectiveness of this technology to address source areas of high COC concentration and the relatively short period of time estimated to achieve RAOs. Alternative 4 is considered less cost-reasonable than Alternative 3 because the effectiveness in treating high concentration source areas within a reasonable period of time is not well established. Alternative 2 is considered least cost reasonable because of the long period of time (estimated to be more than 30 years) to reduce concentrations of COCs in source areas to a threshold concentration of 1,000 ug/l where MNA would be effective Conclusions of Groundwater Comparative Analysis This comparative analysis indicates that Alternative 3 has the highest effectiveness, particularly in treating high concentration source areas and achieving RAOs in a significantly shorter period of time (about 10 years versus 30 years or longer), long-term reliability and given the effectiveness and long-term reliability is the most cost-reasonable. While Alternative 3 has a higher risk of implementation, careful management of the process can reduce these potential risks. Overall the benefit of eliminating high concentration of source areas in a shorter period of time outweighs the higher implementation risk and slightly higher cost Shallow Bank Soil Alternatives 2 and Effectiveness Alternative 2 capping of bank soil and Alternative 3 removal and offsite disposal of contaminated bank soil are both considered effective in treating bank soil in Beaverton Creek where CPOCs are above RBCs and hot spot criteria. Both alternatives eliminate the direct contact exposure for terrestrial receptors but Alternative 2 will rely upon adequately designed and installed engineering controls Long-term Reliability Alternative 3 is considered to be higher in long-term reliability because removal of the areas of bank soil contamination is a permanent action and the soil would be properly managed offsite. Alternative 2 would be subject to potential stream erosion, digging or burrowing damage and would require continued care. However, a management plan that would include periodic inspections and repair would maintain the integrity of the cap. 6-5

39 Implementability Both Alternatives 2 and 3 would be readily implementable with equipment and materials easily obtainable. Both alternatives also would be eligible for a permit exclusion from the Army Corps of Engineers and would meet the substantive requirements of Oregon surface water quality regulations Implementation Risk Alternatives 2 and 3 would not pose an unacceptable risk to remedy workers because the concentrations of metals in soil do not exceed human RBCs. However, Alternative 3 would require excavation and handling of soil contaminated with CPOCs and could result in migration of soil containing contaminants to Beaverton Creek and contaminated soil would be accessible to terrestrial receptors during the period of excavation Reasonableness of Cost Alternative 2 is considered more cost-reasonable than Alternative 3 because it provides a similar level of protection for terrestrial receptors for exposure to bank soil above RBCs and treatment of hot spots, and its cost is lower than the cost of Alternative Conclusions of Shallow Bank Soil Comparative Analysis This comparative analysis of bank soil alternatives indicates that both alternatives are similarly implementable but differ in other aspects. Alternative 3 would be considered to be more effective in treatment of bank soil exceeding RBCs and hot spot criteria and have a higher long-term reliability. However, Alternative 2 has a lower implementation risk and a lower cost. Overall, Alternative 2 is more cost reasonable at nearly half the cost of Alternative 3 given the relatively small difference in effectiveness, long-term reliability and implementation risk. 6.6 REMEDIATION OF HOT SPOTS All three groundwater alternatives would treat hot spot and high concentration/napl source areas. These source areas are hot spots of contamination because TCE in groundwater exceeds the 11,000 ug/l hot spot criteria for the vapor intrusion pathway and high concentrations indicate potential presence of NAPL. Treatment of these sources of high concentration/napl would also over time reduce the flux of contamination discharging via groundwater to Beaverton Creek where TCE concentrations exceed the hot spot criteria of 0.2 ug/l. While all three alternatives will, in combination with MNA, treat hot spots of contamination, the time to achieve RAOs differs significantly among the alternatives. In addition, because of the fine-grained and low permeability nature of the geologic materials beneath the site, it may not be possible for any of the alternatives to reduce all areas of contamination in groundwater to below the TCE vapor intrusion RBC of 110 ug/l. Both bank soil Alternatives 2 and 3 would treat hot spots of contamination and eliminate the direct exposure pathway to CPOCs in bank soil. 6-6

40 7 SELECTED REMEDIAL ACTION ALTERNATIVE On the basis of the evaluation and comparative analysis of the alternatives in Section 6, groundwater Alternative 3 and shallow soil Alternative 2 are selected for implementation at the EA1 Tektronix site. 7.1 DESCRIPTION OF THE SELECTED ALTERNATIVE The selected remedial alternative consists of a combination of groundwater Alternative 3 using ERH and soil Alternative 2 bank soil capping, and the groundwater alternatives common elements. The total cost for this selected combination of remedial alternatives is $3,599,000. Details for this selected alternative will be developed during remedial design Confirm Limits of Shallow Soil Contamination and Evaluate Metal Toxicity. Prior to placement of the cap, additional shallow soil evaluation will be conducted to define the remedial action area in more detail. This work may also include an assessment of metal toxicity in soil that could possibly eliminate hot spots of contamination and significantly reduce or eliminate the areas requiring remedial action. The additional soil evaluation and will be performed during the remedial design phase Engineering Controls for Beaverton Creek: Cap Shallow Soil in Banks Areas of shallow soil contamination in Beaverton Creek banks would be capped with a permeable synthetic geotextile fabric liner that is in turn covered by an approximate foot thick layer of clean soil. The soil layer would be seeded to establish a surface vegetative layer with a root zone. The areas requiring capping within Beaverton Creek are shown on Figure 5-4. Long-term maintenance of the capped areas will include annual inspection and maintenance to replace eroded soil cover, reestablish vegetation, and repair or replace any sections of the cap and/or damaged liner. Cap construction details will be developed during the design phase. Prior to design of the bank soil cap, additional evaluation of the area requiring capping would be conducted that may include additional sampling and analysis. This additional evaluation may result in reducing the total capping area, or possibly eliminating the need for capping, and would be based upon assessment of exposure risk for terrestrial receptors Engineering Controls for Building 38 Building 38 is not currently occupied and exposures to VOC vapors migrating into the building are not presently occurring. Therefore, Engineering Controls are identified as contingency measures that will be implemented if the groundwater remedy fails to reduce VOC indoor air concentrations to below occupational RBCs, or, if a decision is made to occupy the building before the groundwater remedy has achieved RAOs for indoor air. Contingency measures will consist of sealing building floors and adjustments to the HVAC system. Floor sealant would be applied to the bottom floor of Building 38 to reduce migration of VOC vapors through the foundation into the building. If the sealant is not effective in reducing TCE concentrations in air to below the indoor air RBC then adjustments would be made to the HVAC system air exchange rate throughout the building. Long-term monitoring and control of the system would be preformed through completion of the groundwater remedy Pilot Testing for Source Area Treatment Pilot testing of the ERH technology would be performed to verify its effectiveness for this site prior to full scale implementation. Testing would be performed at one of the VOC treatment areas. If verified as effective then ERH would be implemented at all of the identified VOC treatment areas; MNA will be implemented at all other areas where VOCs exceed the vapor intrusion pathway criteria. If ERH is not verified as effective, then a subsequent pilot test for ERD would be conducted at one of the identified 7-1

41 VOC treatment areas. If ERD is verified to be effective, but ERH is not, then the final remedy would consist of implementation of ERD at all VOC treatment areas. A pilot test work plan would be developed and submitted for DEQ review and approval early in the remedial design phase VOC Source Areas Treatment Implementation of ERH for VOC source areas would be conducted after pilot testing results have been evaluated. ERH implementation will include installation of electrodes and vapor recovery wells into the aquifer in the source areas. The electrodes and recovery wells will be co-located for full recovery of vapors and steam. A treatment system consisting of a steam condenser would separate water from VOCs in the vapor state and direct the water to the sanitary sewer and the VOCs would be treated separately Implementation of MNA Once VOC source areas have been treated using the ERH technology and VOC concentrations have been reduced to or below 1000 ug/l then additional treatment will rely upon MNA. MNA will be implemented initially at Building 10. An estimated 10 years is required for MNA to reach RAOs for groundwater based upon results of MNA applied to other areas of the site. Progress over time in achieving RAOs would be monitored under an O&M plan Monitoring Groundwater, Surface Water and Indoor Air Monitoring of groundwater and surface water will be conducted prior to, during, and following implementation of the proposed remedial action. Monitoring will be conducted pursuant to a Remedy Performance Monitoring Plan to be developed during remedial design. Points of compliance for groundwater will be established in the source treatment areas for initial assessment of effectiveness of source area treatment. Longer-term monitoring points will be established downgradient of the source treatment areas to monitor concentrations of COCs in groundwater prior to discharge to Beaverton Creek. An estimated three compliance points will be established for surface water in Beaverton Creek with at least one point downstream from the Tektronix property. Points of compliance for indoor air will be established for Building 38. Groundwater monitoring will be conducted to evaluate remedy performance and until all groundwater RAOs are achieved. Indoor air for Building 38 will be monitored on an annual basis during the estimated 10-year groundwater remediation timeframe to confirm that indoor air concentrations of TCE are below the RBC and that the implemented engineering controls are effective. The frequency of indoor air monitoring would be determined during remedy design Institutional Controls: Easement and Equitable Servitudes, Operations & Maintenance Plan, Remedy Performance Monitoring Plan, Soil Management Plan An EES would be developed that will identify areas impacted by VOC contamination where restrictions would be placed on new development and excavation or subgrade utility work. All new development in identified impacted areas would need to consider appropriate engineering controls to be protective for potential vapor intrusion into buildings until groundwater RAOs are achieved. The EES would also include restrictions for Beaverton Creek bank soil capped areas to restrict invasive activities that would breach the installed cap and require inspection and maintenance. Any excavation would be required to be conducted pursuant to a soil management plan that would include requirements for worker health and safety as well as management of potentially contaminated soil or groundwater. An Operations & Maintenance Plan will be developed for the site to monitor and maintain the implemented remedy, including installed caps, during the period of remedy performance monitoring and beyond closure of this cleanup site. The plan will provide procedures for the implemented remedy 7-2

42 including periodic inspection of capped areas within Beaverton Creek, routine maintenance and repair of the caps and monitoring wells, and a schedule for reporting to DEQ. A Remedy Performance Monitoring Plan will be developed to identify the locations, methods, periodicity, QA procedures and reporting, for groundwater, surface water and indoor air monitoring. Groundwater and surface water monitoring will include all identified compliance points. The Remedy Performance Monitoring Plan will be developed during remedial design. A Soil Management Plan will provide a summary of site conditions after remedy implementation and protocol for worker health and safety measures and management of potentially contaminated soil and groundwater during any future invasive site development activities such as foundation construction or repair or installation of utilities Periodic Monitoring, Review and Contingency Plan DEQ will conduct periodic review of the site on an annual basis to assess the performance and protectiveness of the selected final remedy. Reviews will include evaluation of site monitoring data, progress reports, inspection and maintenance reports, land and water beneficial use changes for the site vicinity, compliance with institutional controls (EES) and any other relevant information. Contingencies will be considered if the remedy does not perform as expected. Some examples of causal situations that would require evaluation of contingency measures include failure of engineering controls (shallow soil caps, HVAC adjustments, failure of floor seals), persistent or increasing concentrations of VOCs in groundwater above the indoor air criteria or discharging to Beaverton Creek, or inability of the groundwater monitoring network to adequately assess remedy performance. Examples of contingency measures include use of SVE beneath Building 38 to reduce infiltration of vapors, use of alternate treatment technologies for VOC source areas (such as ERD or groundwater extraction and treatment), expansion of the monitoring network, or additional evaluation of site conditions. Upon failure or projected failure of the remedy to achieve RAOs, a contingency plan will be developed to assess and propose appropriate contingency measures. 7.2 SATISFACTION OF PROTECTION AND BALANCING FACTORS Protectiveness The selected remedy is protective because it will achieve RAOs through remediation of groundwater VOC source areas to reduce vapor intrusion to indoor air and reduce discharge of VOCs to surface water of Beaverton Creek. Institutional controls and identified engineering control contingency measures will be protective of occupational and excavation workers during groundwater remediation. Monitoring land and water uses and future site development, and monitoring groundwater, surface water and indoor air during remediation will allow timely assessment of the performance of the remedy and development of contingency measures if significant changes occur before RAOs are achieved Balancing Factors The selected remedy represents the best balance among alternatives as compared to the balancing factors. ERH is slightly more costly than ERD but it is a proven technology that is expected to be more effective in reducing VOC concentrations in the low permeability soil of the Willamette Silt underlying the site. MNA as a follow-on technology to ERH has been shown to be effective in complete degradation of VOCs in similar soil in other areas of the site There are no barriers to implementation of the remedy, low risks presented by the ERH technology are manageable, and the cost while not lowest is reasonable considering the shorter timeframe anticipated to reach RAOs. Groundwater, surface water and indoor air monitoring will provide needed data to assess the performance of the selected remedy and develop 7-3

43 appropriate contingency measures should they be required for protection of human health and the environment Remediation of Hot Spots The selected remedial alternative for groundwater will reduce the concentration of hazardous substances and treat hot spots of contamination as described in Section Periodic Review and Contingency Plan There are a number of uncertainties at the site that make it difficult to predict the long-term effectiveness of any of the remedial actions described above including: Heterogeneity in the subsurface and in material parameters, Potential changes in future groundwater beneficial uses, Potential changes in future land use zoning, Changes in community concerns regarding remedial actions at the site, Long-term performance of the groundwater or soil remedies, or Effectiveness of the selected remedial actions for site conditions. Because of these uncertainties, a periodic monitoring review and contingency plan will be developed that will evaluate the performance of the remedy and any changes that may affect the ability of the remedy to meet the RAOs. The objective of the periodic monitoring, review and contingency plan will be to maintain the overall protectivesness of the selected remedy by establishing a series of decision criteria and related response actions for each potential area of uncertainty identified above, and the RAOs listed in Section of this document. DEQ will conduct periodic review of the site on an annual basis to assess the performance and protectiveness of the selected remedy. Reviews will include evaluation of site monitoring data, progress reports, inspection and maintenance reports, land and water beneficial use changes for the site area, compliance with institutional controls and any other relevant information. Contingencies will be considered if the remedy does not perform as expected. Some examples of causal situations that would require evaluation of contingency measures include failure of the remedial technology to reduce concentrations of VOCs in source areas, increasing concentrations of sit-related contaminants in downgradient shallow groundwater or in surface water, inability of the groundwater monitoring network to adequately assess remedy performance, or changes in use of buildings in particular Building 38. Examples of contingency measures include implementing identified engineering controls for Building 38, evaluation of additional treatment technologies for groundwater contamination, expansion of the monitoring network, changes in the monitoring frequency, or additional evaluation of site conditions. Upon failure or projected failure of the remedy to achieve RAOs, a contingency plan will be developed to assess and propose appropriate contingency measures. 7.3 FINANCIAL ASSURANCE Tektronix Incorporated will provide a financial assurance mechanism to ensure the performance of the remedial actions described above. The financial assurance may be in a form that meets the requirements of 40 CFR (f)(1)(i), or can be a performance bond or letter(s) of credit. 7-4

44 8 PUBLIC NOTICE AND COMMENT 8.1 COMMENTS FROM DEQ RCRA PROGRAM Comments were received from DEQ s RCRA Program and provided clarification in statements regarding RCRA closures for the site. The comments and modifications made in the ROD are summarized below. Section 2.3.2: This section was modified to indicate that the Tektronix RCRA Permit was renewed as a post-closure permit since Tektronix no longer manages hazardous waste. Section 3.4: This section was modified to indicate that final closure of all RCRA units will occur after all requirements of the Consent Order and Permit are satisfied. Section 3.4.2: This section was modified to indicate that partial closure of Building 40 was approved and the building was demolished according to an approved closure plan. 8.2 COMMENTS FROM TEKTRONIX INCORPORATED Comments were received from Tektronix Incorporated and from Landau Associates on behalf of Tektronix Incorporated. Most of the comments regarded editorial corrections and clarifications and those changes were made in the ROD. The comments also included a request to change the implementation status of engineering controls for Building 38 from implementation as a part of the remedy to contingency measures to be implemented if the remedy failed to reduce indoor air concentrations to below indoor air RBCs or if a decision was made to occupy Building 38 before the remedy is complete. DEQ has made the change for engineering controls from implementation as part of the remedy to contingency measures as requested. However, this represents a significant change to the remedy and is therefore discussed in the following section 9 Documentation of Significant Change. 8-1

45 9 DOCUMENTATION OF SIGNIFICANT CHANGE DEQ s original proposed remedial action for the site was presented in the Staff Report Recommended Remedial Action for Tektronix, Incorporated Evaluation Area 1, Beaverton, Oregon, dated October 2008.The proposed final site remedial action was public noticed in December One significant change has been made to the proposed final remedial action in response to public comments. The change is to make engineering controls for Building 38, identified in the Staff Report, contingency measures instead of implementing them during remedial action. The identified engineering controls for Building 38 include sealing the bottom floor of the building with a coating to prevent infiltration of VOC vapors emanating from a VOC plume in shallow groundwater beneath the building, and making adjustments to the buildings HVAC system to maintain a positive air pressure in the building. Indoor air concentrations measured in Building 38 exceed the occupational RBC for indoor air and therefore this pathway is considered complete. However, the building is not presently occupied and Tektronix does not intend to use the building until groundwater RAOs are achieved. While it is reasonable to make this change, these engineering controls will still be implemented if the remedial actions do not reduce indoor air concentrations to below occupational RBCs or if Tektronix makes a decision to use Building 38 before groundwater remediation is complete. 9-1

46 10 FINAL DECISION OF THE DIRECTOR The selected remedial action for the Tektronix, Incorporated Evaluation Area 1 is protective, cost reasonable, effective, implementable and reliable to the extent practicable, and hot spots remediated to the extent feasible. The selected remedy therefore satisfies the requirements of ORS and OAR and The detailed evaluation of how the selected remedial action meets the regulatory requirements is provided in Sections 5, 6 and DIRECTOR S SIGNATURE Nina DeConcini Oregon Department of Environmental Quality Northwest Region Administrator Date 10-1

47 11 ADMINISTRATIVE RECORD INDEX The Administrative Record consists of the documents on which the selected remedial action for the site is based. The primary documents used in evaluating remedial action alternatives for Evaluation Area 1 of the Tektronix Incorporated site are listed below. Additional background and supporting information can be found in the Environmental Cleanup System Database (ECSI) project file #167 located at DEQ Northwest Region s Portland office SITE SPECIFIC DOCUMENTS DEQ RCRA Program. December 5, from Barb Puchy to Mavis Kent regarding the Tektronix Staff Report. Landau Associates. Project Management Plan, Tektronix, Inc., Beaverton, Oregon. October 14, Landau Associates. Remedial Investigation Work Plan, Tektronix, Inc., Beaverton, Oregon. February 7, Landau Associates. Risk Assessment Approach and Response to DEQ Comments, Tektronix, Inc., Beaverton, Oregon. March 7, Landau Associates. Technical Memorandum: Phase 1a Evaluation, Tektronix, Inc., Beaverton, Oregon. April 8, Landau Associates. Technical Memorandum: Catch Basin and Sump Survey, Tektronix, Inc., Beaverton, Oregon. April 9, Landau Associates. Data Report, West Park Parcel, Tektronix, Inc., Beaverton, Oregon. April 25, Landau Associates. Human Health Risk Assessment, West Park Parcel, Tektronix, Inc., Beaverton, Oregon. June 13, Landau Associates. Phase I Data Report, Tektronix, Inc., Beaverton, Oregon. December 11, Landau Associates. Technical Memorandum: Phase III Work Plan Addendum, Tektronix Site Remedial Investigation, Beaverton Creek Operational Unit, Beaverton, Oregon. August 31, Landau Associates. Response to August 13, 2004 DEQ Comments on Proposed Revisions to Draft Phase II Scope Technical Memorandum and Draft Phase III Work Plan Addendum, Tektronix, Inc., Beaverton Campus, Evaluation Area 1. September 3, Landau Associates. Technical Memorandum: Phase II Scope, Tektronix, Inc., Beaverton, Oregon. September 9, Landau Associates. Technical Memorandum: Phase V Work Plan Addendum, Indoor Air Investigation, Tektronix Inc., Beaverton, Oregon. April 8, Landau Associates. Technical Memorandum: Ecological Risk Assessment Approach, Tektronix Evaluation Area 1, Beaverton, Oregon. July 11, Landau Associates. Technical Memorandum: Human Health Risk Assessment Approach, Tektronix Evaluation Area 1, Beaverton Oregon. September 1, Landau Associates. Agency Review Draft Feasibility Study Work Plan, Tektronix, Inc., Beaverton, Oregon. June 15, Landau Associates. Human Health Risk Assessment, Tektronix, Inc., Beaverton, Oregon. August 17, Landau Associates. Remedial Investigation Report, Tektronix, Inc., Beaverton, Oregon. March 23,

48 Landau Associates. Ecological Risk Assessment, Tektronix, Inc., Beaverton, Oregon. February 9, Landau Associates. Feasibility Study, Tektronix, Inc., Beaverton, Oregon. July 17, Landau Associates. February 4, from Jay Bower of Landau Associates (on behalf of Tektronix) to Mavis Kent regarding the Tektronix Staff Report. Tektronix, Incorporated. February 3, from Ken Skinner to Mavis Kent regarding the Tektronix Staff Report. WindWard Environmental LLC. Technical Memorandum: Phase 3 Sediment Chemistry and Toxicity Testing at Beaverton Creek Operational Unit. October 9, STATE OF OREGON Oregon s Environmental Cleanup Laws, Oregon Revised Statutes , as amended by the Oregon Legislature in Oregon s Hazardous Substance Remedial Action Rules, Oregon Administrative Rules, Chapter 340, Division 122, adopted by the Environmental Quality Commission in Oregon s Hazardous Waste Rules, Chapter 340, Divisions Oregon s Water Quality Criteria, Chapter 340, Division 41, Columbia River Basin. Oregon s Groundwater Protection Act, Oregon Revised Statutes, Chapter 468B. Default Background Concentrations for Metals, DEQ Memo, October 28, GUIDANCE AND TECHNICAL INFORMATION DEQ. Cleanup Program Quality Assurance Policy. September 1990, updated April DEQ. Consideration of Land Use in Environmental Remedial Actions. July DEQ. Guidance for Conducting Beneficial Water Use Determinations at Environmental Cleanup Sites. July DEQ. Guidance for Conduct of Deterministic Human Health Risk Assessment. May 1998 (updated 5/00). DEQ. Guidance for Conducting Feasibility Studies. July DEQ. Guidance for Ecological Risk Assessment: Levels I, II, III, IV. April 1998 (updated 12/01). DEQ. Guidance for Identification of Hot Spots. April DEQ. Guidance for Risk-Based Decision Making for Petroleum Contaminated Sites. January DEQ. Guidance for Use of Institutional Controls. April USEPA. Guidance for Conducting Remedial Investigation and Feasibility Studies Under CERCLA. Office of Emergency and Remedial Response. OSWER Directive October USEPA. Transport and Rate of Contaminants in the Subsurface. Robert S. Kerr Environmental Research Laboratory. EPA/625/489/ USEPA. Exposure Factors Handbook. Office of Health and Environmental Assessment. EPA/600/8-89/043. May USEPA. Risk Assessment Guidance for Superfund, Volume 1, Human Health Evaluation Manual, Part A, Interim Final. Office of Solid Waste and Emergency Response. EPA/540/1-89/002. December USEPA. Human Health Evaluation Manual, Supplemental Guidance: Standard Default Exposure Factors. OSWER Directive No , March

49 USEPA. Integrated Risk Information System. Office of Research and Development. Cincinnati, Ohio. New York Verschueren, Karel. Handbook of Environmental Data on Organic Chemicals. Van Nostrand Reinhold, New York

50 Page 1 of 1 TABLE 5-2 REMEDIAL ACTION ALTERNATIVES TEKTRONIX SITE BEAVERTON, OREGON In Situ Treatment and Removal Alternative No Action Engineering and Institutional Controls Containment Source Removal Thermal Treatment Bioremediation Monitored Natural Attenuation GROUNDWATER Alternative 1 No Action Alternative 2 Groundwater Extraction and Treatment Alternative 3 Electrical Resistance Heating Alternative 4 Enhanced Reductive Dechlorination CREEK BANK SHALLOW SOIL Alternative 1 No Action Alternative 2 Bank Soil Capping Alternative 3 Bank Soil Excavation 11/19/08 \\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-2.doc

51 TABLE 5-3 GROUNDWATER ALTERNATIVE 2 COST ESTIMATE GROUNDWATER EXTRACTION AND TREATMENT TEKTRONIX EVALUATION AREA 1 Page 1 of 2 UNIT ITEM QTY UNIT COST TOTAL COMMENTS System Design and Project Startup Institutional controls work plan 1 LS $ 20,000 $ 20,000 Groundwater use restrictions 1 LS $ 15,000 $ 15,000 Remedial Action Work Plan 1 LS $ 20,000 $ 20,000 Remedial Design Report 1 LS $ 50,000 $ 50,000 Contractor Bid Specifications 1 LS $ 15,000 $ 15,000 Remedial Action Completion Report 1 LS $ 20,000 $ 20,000 Includes O&M Plan Subtotal $ 140,000 Groundwater Extraction System Expansion and Upgrades New Groundwater Extraction Wells, Shallow 2 EA $ 7,000 $ 14,000 2 require creek area ground prep New Groundwater Extraction Wells, Intermediate 2 EA $ 9,000 $ 18,000 New Groundwater Extraction Wells, Deep 2 EA $ 11,000 $ 22,000 Construction oversight (well installation) 3 days $ 1,000 $ 3,000 Extraction Well Vault (installation, piping, instrumentation 6 LS $ 7,000 $ 42,000 GW Conveyance Piping, including electrical conduit 800 FT $ 70 $ 56,000 Assuming double-containment GW Treatment System and Electrical Upgrades 1 LS $ 30,000 $ 30,000 Upgrades to alarms/controls Completion Report (as-builts) 1 LS $ 10,000 $ 10,000 Pumping Test for New Extraction System 1 LS $ 25,000 $ 25,000 Documentation of capture zone Planning and Coordination 10% $ 185,000 $ 19,000 Construction Oversight/Documentation 10% $ 185,000 $ 19,000 Subtotal $ 258,000 Present Value for Year 2 (6% Discount Factor) $ 243,000 Annual Groundwater Extraction/Treatment O&M Operation and Maintenance Labor 832 hours $ 70 $ 58,000 Average 16 hrs/week Equipment Repair/Replacement 1 LS 15,000 $ 15,000 Electrical Power, Telephone 12 months $ 1,500 $ 18,000 Monthly Effluent Sampling 12 EA $ 1,000 $ 12,000 Quarterly System Sampling/Analysis 4 rounds $ 3,000 $ 12,000 Including extraction wells Well Rehabilitation/Replacement Due to Silt Accumulation 1 LS $ 15,000 $ 15,000 Extraction and monitoring wells Sewer Discharge Fee 1 LS $ 3,000 $ 3,000 Non-routine discharges only Data management 1 LS $ 5,000 $ 5,000 Reporting 1 LS $ 10,000 $ 10,000 Project management 10% $ 148,000 $ 15,000 Subtotal $ 163,000 See Note 3 Present Worth O&M (Years 1-30, Discount Rate = 6%) $ 2,244,000 Present Worth of Groundwater and Surface Water Monitoring $ 792,000 See details on Page 2 Present Worth of Annual DEQ Review Cost $ 97,000 See details on Page 2 Contingency 10% % $ 3,530,000 $ 352,000 Total Estimated Cost $ 3,870,000 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-3.xls

52 TABLE 5-3 GROUNDWATER ALTERNATIVE 2 COST ESTIMATE GROUNDWATER EXTRACTION AND TREATMENT TEKTRONIX EVALUATION AREA 1 Page 2 of 2 UNIT ITEM QTY UNIT COST TOTAL COMMENTS Groundwater Monitoring Event Sampling & purge water handling 30 wells $ 200 $ 6,000 Including labor & vehicle costs Groundwater laboratory analysis 30 wells $ 230 $ 6,900 VOCs and MNA parameters Sampling equipment (pumps, meters, etc.) 4 days $ 200 $ 800 No. days assuming only 1 person Data management/analysis 1 each $ 3,500 $ 3,500 Reporting 1 each $ 4,000 $ 4,000 Includes MNA assessment Subtotal $ 21,200 Surface Water Monitoring Event Preparation and sampling 6 samples $ 200 $ 1,200 Surface water laboratory analysis 6 samples $ 250 $ 1,500 VOCs, metals, incl. markup Sampling equipment 1 day $ 200 $ 200 Data management/analysis 1 each $ 1,000 $ 1,000 Including reporting Subtotal $ 3,900 Per surface water event Discount Factor for Future Costs 6% Quarterly Monitoring, Present Value Years 1-7 $ 560,000 Annual Monitoring, Present Value Years 8-30 $ 205,000 Well Abandonment at Year 30 Overdrilling 100 monitoring & 12 extraction 1 LS $ 155,000 $ 27,000 Present worth, discount rate 6% Total Estimated Monitoring Cost $ 792,000 Rounded to nearest $1,000 ANNUAL DEQ PROJECT REVIEW COSTS DEQ Review, Years 1-7 (average per year) 7 year 10,000 $ 56,000 Present worth, discount rate 6% DEQ Review, Years 8-30 (average per year) 23 year 5,000 $ 41,000 Present worth, discount rate 6% Subtotal $ 97,000 Notes: 1. Costs are rounded to the nearest $1,000 where subtotaled and to the nearest $10,000 where totaled. 2. Cost estimate assumes continued operation of the IRAM pump & treat system for 2 years during design and construction of the expanded groundwater extraction system, and assumes continued quarterly groundwater monitoring for 5 years following completion of the expanded extraction system (seven years total) and reduction to annual monitoring in Year It is assumed that the added power and O&M costs associated with the expansion of the groundwater extraction system at the end of Year 2 will be roughly offset by increased efficiency in treatment system operation and monitoring over time, so the annual cost is assumed to be relatively constant over the 30 year period. 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-3.xls

53 TABLE 5-4 GROUNDWATER ALTERNATIVE 3 COST ESTIMATE ELECTRICAL RESISTANCE HEATING TEKTRONIX EVALUATION AREA 1 Page 1 of 2 UNIT ITEM QTY UNIT COST TOTAL COMMENTS System Design and Project Startup Institutional controls work plan 1 LS $ 20,000 $ 20,000 Groundwater use restrictions 1 LS $ 15,000 $ 15,000 Remedial Design/Remedial Action Work Plan 1 LS $ 15,000 $ 15,000 Remedial Design Report 1 LS $ 50,000 $ 50,000 Remedial Action Bid Documents 1 LS $ 15,000 $ 15,000 Incl. contracting w/ ERH vendor Post-Treatment Groundwater Sampling 1 LS $ 20,000 $ 20,000 Remedial Action Completion Report 1 LS $ 20,000 $ 20,000 Subtotal $ 155,000 Soil Heating IWWTF - Two Tank (Pond 1) Source Area Shallow to Intermediate Zone 6,300 sf 40 ft interval (10 to 50 ft bgs) Area with TCE > 1,000 ug/l Deep Treament Zone 3,000 sf 15 ft interval (50 to 65 ft bgs) In Situ Soil Heating 11,000 CY $ 63 $ 690,000 IWWTF - Former Building 40 Source Area Shallow Treament Zone 6,500 sf 22 ft interval (10 to 32 ft bgs) Area with TCE > 1,000 ug/l Intermediate Treament Zone 4,000 sf 12 ft interval (32 to 50 ft bgs) In Situ Soil Heating 7,100 CY $ 63 $ 450,000 Building 38 Source Area Note 3 Shallow Treament Zone 6,500 sf 17 ft interval (15 to 32 ft bgs) Area with TCE > 1,000 ug/l Intermediate Treament Zone 3,500 sf 12 ft interval (32 to 50 ft bgs) 11 ft BGS In Situ Soil Heating 5,600 CY $ 68 $ 380,000 Beaverton Creek Source Area Source Area, sq ft 2,000 sf Area with TCE > 1,000 ug/l Treament Zone, 7 to 32 ft bgs 25 ft In Situ Soil Heating 1,900 CY $ 68 $ 130,000 Subtotal Soil Heating Cost $ 1,650,000 Present Worth of Soil Heating (assuming work occurs in Year 2) $ 1,560,000 Using a 6% discount factor Project Management, Coordination, & Oversight of ERH $ 100,000 Replacement of Monitoring Wells $ 100,000 Present Value of Annual Monitoring, 10 Years $ 353,000 See page 2 Present Worth of IRAM Pump and Treat O&M (2 Years) $ 299,000 Est annual O&M of $163,000 Contingency 10% $ 257,000 Total Estimated Cost for Electrical Resistance Heating $ 2,820,000 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-4.xls

54 TABLE 5-4 GROUNDWATER ALTERNATIVE 3 COST ESTIMATE ELECTRICAL RESISTANCE HEATING TEKTRONIX EVALUATION AREA 1 Page 2 of 2 UNIT GROUNDWATER MONITORING QTY UNIT COST TOTAL COMMENTS Groundwater Monitoring Event Sampling & purge water handling 30 wells $ 200 $ 6,000 Including labor & vehicle costs Groundwater laboratory analysis 30 wells $ 230 $ 6,900 VOCs and MNA parameters Sampling equipment (pumps, meters, etc.) 4 days $ 200 $ 800 No. days assuming only 1 person Data management/analysis 1 each $ 3,500 $ 3,500 Reporting 1 each $ 4,000 $ 4,000 Includes MNA assessment Project Management and Evaluation 1 each $ 5,000 $ 5,000 Incl. evaluation of ERH effectiveness Subtotal $ 26,000 Cost rounded to nearest $1,000 Surface Water Monitoring Event Preparation and sampling 6 samples $ 200 $ 1,200 3 locations - semiannual Surface water laboratory analysis 6 samples $ 300 $ 1,800 VOCs, metals, incl. markup Sampling equipment 2 day $ 200 $ 400 Data management/analysis 2 each $ 700 $ 1,400 Including reporting Subtotal $ 4,800 Annual cost for two sampling events Discount Factor for Future Costs 6% Annual Monitoring, Present Value Years 1-10 $ 227,000 ANNUAL DEQ PROJECT REVIEW COSTS DEQ Review, Years 1-3 (average per year) 3 year 10,000 $ 26,700 Present worth, discount rate 6% DEQ Review, Years 4-10 (average per year) 7 year 5,000 $ 23,400 Present worth, discount rate 6% Subtotal $ 50,000 Cost rounded to nearest $1,000 Well Abandonment at Year 11 Overdrilling 100 monitoring & 12 extraction 1 LS $ 145,000 $ 76,000 Present worth, discount rate 6% Total Estimated Monitoring Cost $ 353,000 Including DEQ review cost Notes & Assumptions: 1. Based on Power Cost = $0.075 per kilowatt hour. Costs rounded to nearest $10,000 where totaled. 2. ERH unit cost of $60/CY is based on the budget for a recent similar project and a bid estimate from Thermal Remediation Services, Inc. 3. For ERH beneath Building 38 it is assumed that 6,000 ft 2 of the lower floor could be cleared for a nine month treatment period. 4. Electrical resistance heating unit cost for the Bldg 38 source area is increased by 10% to account for added dificulty installing heating probes and SVE recovery wells 5. Electrical resistance heating unit cost for the Beaverton Creek source area is increased by 10% to account for added difficulty installing SVE recovery wells and due to the relatively small size of the treatment area 6. Cost estimate assumes continued operation of the IRAM pump & treat system for 2 years during design and through completion of electrical resistance heating. 7. Cost estimate assumes continued quarterly groundwater monitoring through 1 year following completion of soil heating (3 years total) and reduction to annual monitoring in Year 4. 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-4.xls

55 TABLE 5-5 GROUNDWATER ALTERNATIVE 4 COST ESTIMATE ENHANCED REDUCTIVE DECHLORINATION TEKTRONIX EVALUATION AREA 1 Page 1 of 2 ITEM COST COMMENTS Pilot Testing and Work Plans Institutional controls work plan $ 20,000 Groundwater use restrictions $ 15,000 Remedial Pilot Test Work Plan $ 20,000 Pilot Test - Enhanced Reductive Dechlorination $ 100,000 Remedial Design/Remedial Action Work Plan $ 15,000 Remedial Design Report $ 50,000 Remedial Action Bid Documents $ 15,000 Remedial Action Completion Report $ 20,000 Subtotal $ 255,000 Enhanced Reductive Dechlorination Building 38 Area $ 140,000 Building 40 and IWWTF Areas: Bldg. 40 Plume $ 134,000 Two Tank (Pond 1) Plume $ 184,000 Beaverton Creek (Tract C) $ 38,000 Subtotal $ 496,000 Present Value of ERD Costs (assuming occurs at Year 2) $ 468,000 Using 6% discount factor Soil Fracturing to Aid Injection $ 108,000 ERD Project Management (10%) $ 60,000 Present Worth of IRAM Pump and Treat O&M (4 Years) $ 565,000 Est annual O&M of $163,000 Groundwater and Surface Water Monitoring $ 887,000 Total $ 2,340,000 Contingency (10%) $ 230,000 TOTAL ESTIMATED COST $ 2,570,000 Notes: 1. See Appendix B of the FS Report for a detailed breakdown of estimated costs for enhanced reductive dechlorination. 2. Costs are rounded to the nearest $1,000 and to the nearest $10,000 where totaled. 3. Cost estimate assumes continued operation of the IRAM pump & treat system for 2 years during design and electron donor injection events plus an additional two years during post-injection monitoring (4 years total). 4. Cost estimate assumes continued quarterly groundwater monitoring for 5 years following electron donor injection (seven years total) and reduction to annual monitoring in Year 8. 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-5.xls

56 TABLE 5-5 GROUNDWATER ALTERNATIVE 4 COST ESTIMATE ENHANCED REDUCTIVE DECHLORINATION TEKTRONIX EVALUATION AREA 1 Page 2 of 2 UNIT REMEDIAL PERFORMANCE MONITORING QTY UNIT COST TOTAL COMMENTS Groundwater Monitoring Event Sampling & purge water handling 30 wells $ 200 $ 6,000 Including labor & vehicle costs Groundwater laboratory analysis 30 wells $ 230 $ 6,900 VOCs and MNA parameters Sampling equipment (pumps, meters, etc.) 4 days $ 200 $ 800 No. days assuming only 1 person Data management/analysis 1 each $ 3,500 $ 3,500 Reporting 1 each $ 4,000 $ 4,000 Includes MNA assessment Subtotal $ 21,200 Surface Water Monitoring Event Preparation and sampling 6 samples $ 200 $ 1,200 Surface water laboratory analysis 6 samples $ 250 $ 1,500 VOCs, metals, incl. markup Sampling equipment 1 day $ 200 $ 200 Data management/analysis 1 each $ 1,000 $ 1,000 Including reporting Subtotal $ 3,900 Per surface water event Discount Factor for Future Costs 6% Quarterly Monitoring, Present Value Years 1-7 $ 560,000 Annual Monitoring, Present Value Years 8-30 $ 205,000 ANNUAL DEQ PROJECT REVIEW COSTS DEQ Review, Years 1-7 (average per year) 7 year 10,000 $ 56,000 Present worth, discount rate 6% DEQ Review, Years 8-30 (average per year) 23 year 5,000 $ 41,000 Present worth, discount rate 6% Subtotal $ 97,000 Cost Rounded to nearest $1,000 Well Abandonment at Year 30 Overdrilling 100 monitoring & 12 extraction 1 LS $ 145,000 $ 25,000 Present worth, discount rate 6% Total Estimated Monitoring Cost $ 887,000 Rounded to nearest $1,000 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-5.xls

57 TABLE 5-6 BANK SOIL ALTERNATIVE 2 COST ESTIMATE BANK SOIL CAPPING TEKTRONIX EVALUATION AREA 1 Page 1 of 1 UNIT ITEM QTY UNIT COST TOTAL COMMENTS Preparation for Bank Soil Capping Remedial Action Work Plan 1 LS $ 10,000 $ 10,000 Institutional Controls Work Plan 1 LS $ 10,000 $ 10,000 Contractor Bid Specifications 1 LS $ 4,000 $ 4,000 In-Water Work Permit 1 LS $ 7,000 $ 7,000 Note 1 Contractor Mobilization 1 LS $ 4,000 $ 4,000 Subtotal $ 35,000 Bank Soil Capping Clearing Vegetation and Site Prep 11,000 SY $ 2 $ 22,000 Total area of approx. 100,000 ft 2 Place Geosynthetic Liner 11,000 SY $ 5 $ 55,000 Place Clean Import Soil 3,670 CY $ 25 $ 92,000 1 ft cover of clean topsoil Re-establish Vegetation 11,000 SY $ 5 $ 55,000 For erosion control Subtotal $ 224,000 Management & Oversight of Work 10% % $ 224,000 $ 22,000 Cost rounded to nearest $1,000 Capping Completion Report 1 LS $ 8,000 $ 8,000 DEQ Review of Work and Submittals 1 LS $ 10,000 $ 10,000 Subtotal $ 40,000 Cost rounded to nearest $1,000 Total Estimated Capital Cost $ 299,000 Annual Maintenance of Soil Cap Re-planting Vegetation & Liner Repair 5% % $ 224,000 $ 11,000 Note 3 Coordination & Oversight 1 LS $ 2,000 $ 2,000 Annual Status Reporting 1 LS $ 2,000 $ 2,000 Including DEQ review cost Present Value Cost of Maintenance 29 Years $192,000 Years 2-30; 6% discount factor Subtotal Capital and Present Value of Maintenance $ 490,000 Cost rounded to nearest $10,000 Contingency 10% % $ 50,000 Cost rounded to nearest $10,000 Total Estimated Cost $ 540,000 Notes: 1. The work in Beaverton Creek would be exempt from permitting by the Army Corps of Engineers due to exemption for remediation. However, a cost is included to address substantive requirements of Oregon surface water quality regulations. 2. Assumes annual soil cap replacement and repair cost of 5% of the initial cost of the cap. 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-6.xls

58 TABLE 5-7 BANK SOIL ALTERNATIVE 3 COST ESTIMATE BANK SOIL EXCAVATION TEKTRONIX EVALUATION AREA 1 Page 1 of 1 UNIT ITEM QTY UNIT COST TOTAL COMMENTS Preparation for Creek Sediment Removal Remedial Action Work Plan 1 LS $ 10,000 $ 10,000 Includes Sampling & Analysis Plan Contractor Bid Specifications 1 LS $ 4,000 $ 4,000 In-Water Work Permit 1 LS $ 7,000 $ 7,000 Note 1 Contractor Mobilization 1 LS $ 4,000 $ 4,000 Subtotal $ 25,000 Bank Soil Excavation & Disposal Clearing Vegetation and Site Prep 11,000 SY $ 2 $ 22,000 Conventional Excavation & Handling 9,200 CY $ 9 $ 83,000 Excavation to 2.5 ft average depth Transport & Dispose to Hillsboro Landfill 13,800 ton $ 38 $ 524,000 Estimating soil at 1.5 tons/cy Re-establish Vegetation 11,000 SY $ 5 $ 55,000 For erosion control Subtotal $ 684,000 Costs rounded to nearest $1,000 Management & Oversight of Work 10% % $ 160,000 $ 16,000 Markup not applied to disposal costs Confirmation Soil Sampling Confirmation Sampling 92 EA $ 100 $ 9,000 1 sample per 100 CY soil/sed removed Analytical Cost 92 EA $ 150 $ 14,000 Analysis for metals only Additional Excavation 10% % $ 700,000 $ 70,000 Percentage of initial removal cost Remedial Action Completion Report 1 LS $ 8,000 $ 8,000 DEQ Review of Work and Submittals 1 LS $ 10,000 $ 10,000 Subtotal $ 111,000 Costs rounded to nearest $1,000 Subtotal Estimated Cost $ 840,000 Cost rounded to nearest $10,000 Contingency 10% % $ 80,000 Cost rounded to nearest $10,000 TOTAL ESTIMATED COST $ 920,000 Notes: 1. The work adjacent to Beaverton Creek would be exempt from permitting by the Army Corps of Engineers due to exemption for remediation. However, a cost is included to address substantive requirements of Oregon surface water quality regulations. 11/19/2008\\Edmdata\projects\667\001\FileRm\R\DEQ ROD 11-08\Table 5-7.xls

59 PROJECT SITE Tektronix, Inc./FS Report V:\667\001\240\242\DEQ ROD\Figure 2-1.dwg (A) "Figure 2-1" 11/14/ /2 1 Tektronix, Inc. Beaverton, Oregon Scale in Miles Map from: Thomas Guide, Digital Edition, 2002 Vicinity Map Project Location Beaverton Oregon Figure

60 Tektronix, Inc./FS Report V:\667\001\240\242\DEQ ROD\Figure 2-2.dwg (A) "Figure 2-2" 11/14/2008 Legend Operational Unit Boundaries Demolished Building Scale in Feet Tektronix, Inc. Beaverton, Oregon Flow Arrow Site Plan Evaluation Area 1 Operational Units Figure

61 Legend Evaluation Area 1 Sanitary Sewer Line Storm Sewer Line Process Waste Line Groundwater Extraction and Treatment System Piping Notes Tektronix, Inc./RI Report V:\667\001\240\242\DEQ ROD\Figure 2-3_2-4.dwg (A) "Figure 2-3" 11/20/ For purposes of clarity, the following utilities have not been shown: compressed air, natural gas, water mains, HTW, CHW, process gas, primary electric system, Danray/Telecomm, irrigation, tunnel/utility envelope. These features are available electronically and can be provided upon request. 2. The information shown on the drawing was compiled from historical hard copy drawings and/or electronic drawing files provided to MFA by Tektronix. These source drawings were prepared for many purposes with varying levels of detail, and therefore, contain many inconsistencies. No attempt has been made to reconcile the inconsistencies between the various sources. Adapted from: Maul Foster & Alongi, Inc Scale in Feet 800 Tektronix, Inc. Beaverton, Oregon Sanitary, Storm, and Process Waste Lines Figure

62 Legend Evaluation Area 1 Approximate Former Surface Impoundments Approximate Former Sludge Disposal Areas Tektronix, Inc./RI Report V:\667\001\240\242\DEQ ROD\Figure 2-3_2-4.dwg (A) "Figure 2-4" 11/20/ Scale in Feet Adapted from: Maul Foster & Alongi, Inc Tektronix, Inc. Beaverton, Oregon Approximate Sludge Management Areas Figure

63 THOMSON ZWORYKIN Tektronix, Inc./FS Report V:\667\001\240\242\DEQ ROD\Figure 3-1.dwg (A) "Figure 3-1" 11/20/2008 A1WP-DP08 Cadmium Chromium Copper Lead Mercury Nickel Zinc A1WP-DP02 Cadmium Chromium Copper Lead Mercury Nickel Zinc Legend A1WW-HA71 Cadmium Chromium Copper Lead Mercury Nickel Zinc Notes < < Sample Location Depth of Sample (ft) Analyte Value in mg/kg Yellow Indicates that Concentration is Above Screening Level Value Black and white reproduction of this color original may reduce its effectiveness and lead to incorrect interpretation. The chromium, lead and zinc screening level values are estimates of background soil concentrations. All units are mg/kg S.W. MURRAY BLVD A1WP-HA08 Cadmium Chromium Copper Lead Mercury Nickel Zinc A1WP-DP01 Cadmium Chromium Copper Lead Mercury Nickel Zinc A1WP-DP04 Cadmium Chromium Copper Lead Mercury Nickel Zinc < < < < BARDEEN Surface Soil Cleanup Levels Chemical Soil Sediment Cadmium Chromium Copper Lead Mercury Nickel Zinc BEAVERTON CREEK TRACT "E" SCHOTTKY A1TC-DP01 Cadmium Chromium Copper Lead Mercury Nickel Zinc TRACT "F" < MILLIKAN WAY Scale in Feet A1WW-HA19 Cadmium Chromium Copper Lead Mercury Nickel Zinc A1WW-HA71 Cadmium Chromium Copper Lead Mercury Nickel Zinc 1.0 < < TRI-MET LIGHTRAIL A1WW-DP70 Cadmium Chromium Copper Lead Mercury Nickel Zinc < A1WW-HA72 Cadmium Chromium Copper Lead Mercury Nickel Zinc Tektronix, Inc. Beaverton, Oregon < A1WW-HA26 Cadmium Chromium Copper Lead Mercury Nickel Zinc 1.0 < < SHANNON < A1WW-HA24 Cadmium Chromium Copper Lead Mercury Nickel Zinc A1WW-HA25 Cadmium Chromium Copper Lead Mercury Nickel Zinc 1.0 < J 26.5 J 10.7 < < J 19.6 J 7.32 J < J 54.7 Metals in Surface Soil and SLV Exceedances Beaverton Creek Operational Unit 3.0 < < S.W. TER BEAVERTON CRE Figure

64 Area is approximately 2 4,000 ft Area is approximately 2 2,500 ft Area is approximately 2 6,500 ft Area is approximately 4,000 ft 2 Area is approximately 2 6,300 ft Area is approximately 2 6,300 ft Area is approximately 2 3,500 ft Area is approximately 2 3,000 ft Former Building 46 Building 38 Former Building 46 Building 38 Former Building 46 Building 38 Former Building 40 Former Building 40 Former Building 40 Terman Drive Terman Drive Terman Drive Beaverton Creek Beaverton Creek Beaverton Creek Shannon Place Shannon Place Shannon Place Tektronix, Inc./FS Report V:\667\001\240\242\DEQ ROD\Figure 3-2.dwg (A) "Figure 5-2" 11/18/2008 Shallow Zone (20 ft bgs) Intermediate Zone (40 ft bgs) Deep Zone (60 ft bgs) Combined area is approximately 2 2,000 ft Scale in Feet Area of proposed electrical resistance heating for VOC source removal, Groundwater Remedial Action Alternative 3 Tektronix, Inc. Beaverton, Oregon Legend TCE Concentration (ug/l) Note 1. TCE = trichloroethene 2. Black and white reproduction of this color original may reduce its effectiveness and lead to incorrect interpretation. TCE Concentrations in Groundwater Layers, West - Alternatives 3 and 4 Figure

65 Beaverton Creek Beaverton Creek Beaverton Creek Building 16 Building 16 Building 16 Former Building 10 Former Building 10 Former Building 10 Tektronix, Inc./FS Report V:\667\001\240\242\DEQ ROD\Figure 3-3.dwg (A) "Figure 3-3" 11/14/2008 TRI-MET Light Rail Building 2 TRI-MET Light Rail Shallow Zone (20 ft bgs) Intermediate Zone (40 ft bgs) Deep Zone (60 ft bgs) Source Area Associated with the Mears Trust Site Hocken Ave Scale in Feet Building 2 Hocken Ave. Tektronix, Inc. Beaverton, Oregon Legend TCE Concentration (ug/l) TRI-MET Light Rail Note Building 2 1. TCE = trichloroethene 2. Black and white reproduction of this color original may reduce its effectiveness and lead to incorrect interpretation. TCE Concentrations in Groundwater Layers, East Figure Hocken Ave.