Prior to initiation of the Phase II ESA, BB&A and the project liaison met with representatives of The Confederated Tribes of the Warm Springs (CTWS) to develop a program for public awareness and outreach. As part of the public awareness and outreach program, a website was developed (with regular update postings), and press releases were provided to the local radio and newspaper. Progress press releases and updates to the website will continue until the project is completed.

The purpose of the Phase II ESA was to identify potential environmental liabilities, or “recognized environmental conditions,” currently associated with the subject properties, specifically with respect to the liability and lien provision of Oregon Revised Statutes (ORS) 465.255.6. The Phase II ESA was conducted in general accordance with ASTM Standard Guide for Environmental Site Assessments: Phase II Environmental Site Assessment Process (ASTM Designation E1903-97, re-approved 2002).

The results of the Phase II ESA, identified numerous structures with asbestos containing materials (ACMs), lead based paint, and chemical impact from historical operations. At the conclusion of the project, a detailed report was prepared documenting the findings of the investigations. The report included specifications for abatement of ACMS, lead based paint, decommissioning of abandoned HOTs, and mitigation of chemical impacts.

At both construction sites, BB&A Environmental provided services required for characterization, proper management, and off-site disposal of the waste materials.

Specific services included collection of samples of the potentially hazardous waste media, coordination of appropriate laboratory analyses, and completion of waste determinations, and assistance with disposal of waste materials at an authorized disposal facility. At PK Park, BB&A Environmental also assisted with characterization and evaluation of options for management of impacted groundwater that collected in footing excavations.

The hospital facility and USTs are located within the five (5) to 10 year time of travel (TOT) zone of the Sports Way well operated by the Springfield Utility Board (SUB) as part of the municipal water supply for the city of Springfield. A well installed for use under emergency conditions is located approximately 400 feet from the USTs. An active spill of diesel fuel emanating from a UST vent pipe was observed the morning of October 23, 2007, as a result of one (1) of the USTs becoming overfilled with fuel transferred into it from the other UST. The spill occurred after certain testing procedures had been complete and resulted from failure of an electrically operated valve which normally would have allowed the product to freely circulate between the USTs and a nurse tank for the electrical generators. Closure of the valve resulted in one (1) of the USTs becoming overfilled. BB&A Environmental was retained by Turner Construction Company (Turner) to provide environmental consulting services related to assessment of subsurface conditions following the diesel fuel spill. Specific services included completion of push probes, collection and analysis of soil and groundwater samples, preparation of a groundwater monitoring program, installation of groundwater monitoring wells, preparation of an Initial Site Characterization Report as required under Oregon Administrative Rules (OAR) 340-122-230, preparation of a groundwater monitoring and reporting plan, installation of five (5) permanent groundwater monitoring wells, and quarterly monitoring and reporting. The magnitude and extent of impact to subsurface media were determined during site investigation and cleanup activities, and additional investigation of subsurface conditions involving installation of five (5) groundwater monitoring wells. Based on confirmation sampling results and quarterly groundwater monitoring, BB&A Environmental documented that residual impact to subsurface media by diesel fuel does not pose an unacceptable risk to area groundwater and surface water resources and the Oregon Department of Environmental Quality (DEQ) has issued a “no further action” (NFA) determination for the site.

The released product rapidly infiltrated the porous crushed rock ballast beneath the railroad tracks and quickly reached the north bank of Cow Creek located at the base of the embankment. The City of Riddle (population 1,020) draws water from a series of infiltration galleries on Cow Creek to produce municipal water for area residents. Cow Creek is also a migratory route for fall-run Chinook salmon. Impact to human and ecological receptors was, therefore, a primary concern in addressing the effects of the spill.

Spill response activities were coordinated under a Unified Command System (UCS) which included representatives from the US Environmental Protection Agency (EPA), Oregon Department of Environmental Quality (DEQ), the National Response Corporation (NRC), and the responsible party. BB&A Environmental was retained by the responsible party and, as part of the Environmental Unit along with representatives from the EPA and the DEQ, assisted with planning and execution of actual cleanup activities (e.g., sampling strategies, evaluation of options for management and disposal of impacted soils, collection and analysis of soil and groundwater samples, and closure of the project).

as an initial abatement measure, remaining fuel was transferred from the damaged tanks to secure forward compartments. first responders placed absorbent and hard (containment) booms in cow creek beneath the release site to intercept and recover additional product entering the stream. a series of absorbent and containment booms were also placed across cow creek at a number of locations downstream including the infiltration gallery at the municipal water intake in riddle.>

Subsequent spill response efforts included the excavation of approximately 100 cubic yards of diesel-contaminated crushed rock beneath the spill site. The diesel-contaminated gravel was transported to a nearby location for on-site treatment using bioremediation techniques in accordance with a Solid Waste Letter of Authorization (SWLA) and Soil Treatment Plan prepared by BB&A Environmental. Further excavation was deemed infeasible due to the shallow bedrock surface and steep hillside embankment. As an alternative, diesel remaining in the hillside below the release site was purged using a series of aggressive flush events using water released from rail tank cars. A total of 36,000 gallons of water were released in a series of three (3) controlled deluge events.

On October 28, 2004, the City of Riddle temporarily halted water production at the water treatment facility following reports of visual and olfactory impact to raw and finished water at the facility. As a precautionary measure, classes at Riddle public schools were canceled on Friday October 29, 2004. Bulk water from alternate water supplies was provided to area residents at the local firehouse for several days following the release.

Water quality was monitored at numerous locations during the emergency response phase of the investigation. Initial laboratory analyses confirmed the presence of fluorene, naphthalene, and phenanthrene in the raw water intake to the Riddle water supply, but at levels significantly below EPA Region 9 Preliminary Remediation Goals (PRGs). BB&A Environmental prepared a Monitoring and Maintenance Plan to provide a framework for collecting and evaluating water quality data during the cleanup phase of the project. The plan, subsequently approved by the DEQ, recommended the collection of water samples from several locations on Cow Creek and at the City of Riddle water treatment plant at quarterly intervals to capture the effects of seasonal events within the watershed. Sampling data collected since November 2004 indicates no remaining impact to water at levels exceeding laboratory method reporting limits (MRLs). Upon completion of monitoring activities, BB&A Environmental submitted a cleanup report to the DEQ Cleanup Program documenting sample collection and cleanup activities during the cleanup phase of the project. The DEQ issued a “no further action” (NFA) determination for the site.

The RI included the collection of soil and groundwater samples for laboratory analysis from push probes and the installation of groundwater monitoring wells for water quality monitoring. In addition, a former on-site water well was retained for sampling a deeper aquifer given the presence of organic solvents on-site. The results of these investigations indicated petroleum hydrocarbon impact and the presence of the chlorinated solvents (primarily trichloroethene [TCE]) in soil and groundwater. The RI/FS determined that elevated concentrations of TCE in soil posed a long-term threat to groundwater quality and that groundwater had been impacted. The RI/FS identified a localized area of elevated soil impact that was likely the ongoing source of groundwater impact by TCE and related chlorinated compounds. Recommended corrective actions included the removal and off-site disposal of residual soil impact containing elevated concentrations of TCE. This work was completed in 2004 and compliance monitoring was then undertaken for a period of two (2) years.

A human health risk assessment was also completed as part of the RI/FS process. The risk assessment included development of a conceptual site model (CSM) and identification of potential receptors. Based on current and likely future land use and zoning, construction worker (on-site and along Main Street) and excavation worker/landscaper (on-site) were identified as potential receptors. Using these receptors, an evaluation of 10 exposure pathways was performed. Leaching to Groundwater and Ingestion/Inhalation from Tap Water were excluded as applicable exposure pathways. The following exposure pathways were determined to be applicable to the site: for soil - Construction Worker, Excavation Worker, and Volatilization to Outdoor Air and for groundwater - Groundwater in Excavation, Volatilization to Outdoor Air, and Construction Worker. Using the selected receptors and applicable exposure pathways, TCE was the only contaminant of concern (COC) identified in groundwater. No COC were identified in residual soil following soil cleanup activities.

Cumulative and ecological risks were also evaluated. Although no “hot spots” or cumulative risks were identified in soil, cumulative risk associated with dissolved TCE in groundwater slightly exceeded the excess cancer risk of 1x10-6. Non-carcinogenic risk in groundwater was calculated to be below a hazard indices (HI) of 1.0. Ecologically, groundwater to surface water was the only identified ecological pathway of concern. None of the detected compounds exceeded Level II Screening Values when comparing detected compounds in the nearest well to surface water in wetland areas.

A phased approach was utilized to eliminate costs associated with further evaluation of target drilling sites which were found to have low potential for developing a suitable groundwater resource. This approach also allowed information generated during each phase to be sufficient for the requirements of each subsequent phase.

Phase I involved an evaluation of the available groundwater resources at target drilling sites based on existing published data and interviews with knowledgeable personnel. The objective of this phase was to identify sites which are underlain by a groundwater resource that can reasonably be expected to meet projected needs. A groundwater resource matrix was proposed for use in the selection process and included parameters such as depth to groundwater, aquifer type(s), aquifer permeability, volume requirements, and potential restrictions on groundwater development (e.g., interference with existing allocation(s), potential contamination problems). Selection of sites for further evaluation was partially justified on the basis of this groundwater resource matrix.

Phase II involved development of specifications for drilling and aquifer testing to further evaluate the selected drilling targets. Specifications included drilling technique and depth and aquifer testing requirements.

Phase III involved the actual investigative field activities required to identify or verify the presence or absence of a viable groundwater-based water supply and evaluation of aquifer parameters

Phase IV involved preparation of a written report to document the activities completed during the study and included recommendations for sites which may be developed for a groundwater-based water supply.

The scope of services has included preparing a narrative overview of available groundwater resource, design and analysis of aquifer tests to estimate groundwater yields, development of a three dimensional MODFLOW model covering a 64 square mile area to evaluate various conceptual well field alternatives, evaluating Ranney Collectors as an alternative extraction technology, and water quality sampling and analysis.

The SWPCPs were prepared to meet compliance requirements of the DEQ administered National Pollutant Discharge Elimination System (NPDES) Storm Water Discharge Permit.

A review of each site was performed and the SWPCPs written to promote cleaner industrial activities designed to minimize or eliminate the introduction of industrial-related contaminants into public waters. The SWPCPs accomplish this through the evaluation of the facility, including identification of potential sources of stormwater pollution, evaluation of potential risk of stormwater contamination from these sources, and evaluation of current stormwater management practices. The SWPCPs include a site description with information on the tax lot(s), geographic and geologic features, physical features, industrial activities, and maps of site location and drainage. The SWPCPs also delineate drainage basins, impervious areas, receiving waters, potential pollutants, engineering controls, best management practices, spill prevention and response procedures, preventive maintenance, employee education, record keeping and reporting, river basin limitations, stormwater discharge limitations, and the allowable mixing zone.

Stormwater management activities included consideration of the following practices to limit pollutant discharges to the stormwater outfalls:

• Containment
• Oil and grease separation
• Debris and sediment control
• Waste chemical disposal
• Stormwater diversion
• Covered storage or manufacturing areas

The SWPCPs were finalized, stamped by a registered professional engineer, and submitted to the Department of Environmental Quality (DEQ).

Stormwater sampling has been conducted to ensure that benchmark levels were met for the parameters required by the 1200-Z stormwater permit. Upon achieving four (4) consecutive sampling events of compliance for many of the monitoring parameters, monitoring waivers have been submitted to the DEQ for those parameters that achieved compliance. Best management practices (BMPs) and technically and economically feasible stormwater controls have been implemented to achieve compliance for the additional parameters.

As a result of the crash, the forward of three (3) compartments in the tanker trailer split and rapidly spilled approximately 2,100 gallons of Jet A turbine fuel (jet fuel) that discharged to the graveled shoulder and adjacent open stormwater drainage ditch on the west side of the highway. Some of the fuel also drained across the highway into a catch basin that discharged to an open stormwater ditch north and east of the primary spill site.

Approximately 200 gallons of fuel migrated into a sanitary sewer and accumulated in a sewer lift station located approximately 200 feet west of the spill site. The proximity of the spill site to the Willamette River (i.e., approximately 300 feet) and the presence of numerous private residential wells near the spill site raised concerns regarding potential impact to both surface water (via discharge from the stormwater system) and groundwater.

Spill response activities were coordinated under a Unified Command System (UCS) which included representatives from the US Environmental Protection Agency (EPA), Oregon Department of Environmental Quality (DEQ), Oregon Department of Transportation (ODOT), and the responsible party. BB&A Environmental was retained by the responsible party and, as part of the Environmental Unit along with representatives from the EPA and the DEQ, assisted with planning and execution of actual cleanup activities (e.g., sampling strategies, evaluation of options for management and disposal of impacted soils, collection and analysis of soil and groundwater samples, and closure of the project).

Initial emergency response measures included diverting traffic around the crash scene, shutting down the sewer pump station, and blocking the storm drain system. Spill responders also distributed absorbents over the roadway in the spill area, flushed and vacuumed the storm drains to clean out residual fuel, stabilized the damaged power pole, diverted traffic around the spill area, and removed product from the two (2) rear compartments of the tanker trailer. Firefighting and emergency response resources mobilized to the site maintained a presence until remaining product was transferred off-site and wreckage was removed from the crash site. Although emergency response measures limited additional loss and migration of the spilled product, the majority of the spilled fuel drained into soils, primarily on the west side of Highway 99E where the ruptured tanker trailer had been located.

Subsequent spill response efforts involved use of vacuum trucks to remove product from the sewer lift station and to transport accumulated sewage to the treatment lagoon in order to bypass the pump system. Cleanup and investigative activities were undertaken the day of the spill and continued for four (4) days. Native soils impacted with jet fuel were found to depths of approximately seven (7) to 12 feet below land surface (BLS). The vertical extent of impacted soils was exacerbated by disturbed soils related to installation of deep utilities on the west side of the highway and permeable soils. Cleanup efforts involving removal and off-site disposal of petroleum contaminated soil (PCS) were performed and resulted in removal of approximately 1,086 tons of PCS. Confirmation soil samples were collected from the excavation areas as cleanup progressed. The extent of soil cleanup was limited by utilities in the spill areas, including high pressure natural gas, a fiber optic line, high pressure water mains, and sanitary sewer mains. Numerous push probes were completed to determine the lateral and vertical extent of impacted soils surrounding each of the spill areas.

Five (5) groundwater monitoring wells and a recovery well were installed after soil cleanup activities were completed. Separate phase liquid has been observed in three (3) of the wells in the main spill area requiring active remediation using direct removal of free product, vacuum extraction, and dual-phase extraction. BB&A Environmental prepared a supplemental report to the initial spill/cleanup report submitted to the DEQ for review. Removal of separate phase liquids, in-situ remediation, additional site investigation, and compliance groundwater monitoring, will be needed to support a risk-based closure of the site.

Response to the spill occurred in three phases: the crash response and fire suppression phase, the emergency response phase, and the long-term response phase. The cleanup was performed using cleanup contractors retained by the responsible party in coordination with a Unified Command System (UCS) which included representatives from the US Environmental Protection Agency (EPA), Oregon Department of Environmental Quality (DEQ), Oregon Department of Transportation (ODOT), and the responsible party. BB&A Environmental was retained by the responsible party and, as part of the Environmental Unit along with representatives from the EPA and the DEQ, assisted with planning and execution of actual cleanup activities (e.g., sampling strategies, evaluation of options for management and disposal of impacted soils, collection of soil and surface water samples, data evaluation, and project closure).

The crash response and fire suppression phase took place immediately after the accident on September 8, 2003. During this phase the highway was closed, firefighters suppressed the fire and cooled the truck tanker, and the Oregon State Police conducted an accident investigation. Emergency responders were successful in separating the truck tanker from the tanker trailer, which was wholly destroyed by the fire, and preventing additional environmental damage.

The UCS directed spill response activities during the emergency response phase with the primary objective being to prevent the spilled gasoline from reaching the Umpqua River. To meet this objective, absorbent and hard (containment) booms were deployed along the shoreline downhill of the spill as precautionary measures and approximately 1,575 cubic yards of gasoline-contaminated soil was excavated from the spill area. The resulting excavation was approximately 40 feet deep at the deepest point relative to the grade of Highway 38 and the extent of the excavation was dictated by field and field instrument observations as to the presence or absence of impact as well as safety considerations (e.g., slope stability/headwall collapse). Additional emergency response measures included installation of groundwater monitoring and provisional remediation wells, collection of surface water samples for analysis on a priority rush basis, documentation of the location and use of surface water intakes, and notifying nearby residents and businesses about the spill.

Following the emergency response phase it was recognized that a small volume of residual impacted soil inaccessible to removal represented a potential secondary source of contamination though it was believed that the soil removal had essentially eliminated the likelihood of acute impact to water quality in the Umpqua River. Based on spill response actions and site conditions, the long-term response phase was undertaken. This phase included characterization and off-site disposal of excavated contaminated soil and other wastes according to approved “Waste Disposal Plan,” monitoring impact to groundwater and the Umpqua River from residual gasoline contamination according to approved “Soil and Water Sampling and Monitoring Plan” which included sampling based on cumulative and event-specific precipitation triggers, maintaining existing hard and absorbent booms, site restoration, establishing preliminary action levels which would trigger additional site response (e.g., presence of petroleum seep into Umpqua River), documentation of surface water intakes, preparation of the initial spill response report and compilation of necessary long-term monitoring data and other information to screen for human health and ecological risk and determine need for remedial actions to address any long-term risk posed by site. The DEQ anticipated a minimum one (1) year of groundwater and surface water monitoring data would be required. Site investigation and long-term surface water and groundwater monitoring data subsequently supported a risk-based closure of the site and a final closeout report prepared by BB&A Environmental. The DEQ subsequently issued a “no further action” (NFA) determination for the site.

Initial remedial efforts included removal of soils saturated with gasoline along the north side of the highway. Further excavation within the spill area was prohibited due to the narrow highway, steep slope, and underlying unstable geology. To determine the lateral and vertical extent of the gasoline, borings were advanced using coring techniques along the southern edge of the highway and along the reservoir shoreline at the “high pool” elevation.

The coring rig was brought to the shoreline by barge across the reservoir. The borings along the highway were completed as soil vapor extraction (SVE) wells, and within three (3) days of the spill extraction SVE was initiated using a catalytic oxidizer and accompanying blower. The borings along the reservoir shoreline were completed as groundwater monitoring wells to depths approaching 70 feet. Additional assessment and remedial efforts performed at the site included vapor monitoring at various locations below the spill area within broken andesite talus, surface water sampling, and aeration (sparging) within the reservoir to remove and minimize the migration of dissolved gasoline constituents. Remedial efforts and natural attenuation reduced the concentrations within the spill area to regulatory levels. Following a period of compliance groundwater monitoring, the site was issued a “no further action” (NFA) determination from the DEQ.

Historical operations as a pipe manufacturer resulted in impact from polychlorinated biphenyls (PCBs) associated with large power transformers and chlorinated solvent impact to the Troutdale Aquifer located 50 feet below land surface (BLS).

A focused Phase II Environmental Site Assessment (ESA) conducted at the site included a geophysical survey over the majority of the site using primarily a magnetometer, a ground penetrating radar (GPR) system, and electromagnetic tracers and pipe locators. The geophysical survey helped to confirm and identify the location of potential UST cavities, former excavations, dry wells, cesspools, septic tanks, utility lines, abandoned wells, and to provide clearance for push probe sampling locations. In late 2007, 28 push probe borings were installed near areas of concern or Recognized Environmental Conditions (RECs) identified by the geophysical survey and in the Phase I ESA to facilitate sample collection activities. Push probe borings were placed in the areas of former UST cavities, identified sumps and dry wells, near the wash rack, adjacent to the paint booth, within the footprint of the former pipe manufacturing building, and in the area of former sandblasting and a magnetic anomaly (i.e., possible buried drum).

The results of the focused Phase II ESA documented soil and groundwater impact predominantly by diesel-range and heavy oil-range total petroleum hydrocarbons (TPH), and to a lesser extent, polynuclear aromatic hydrocarbons (PAHs), gasoline-range TPH, volatile organic compounds (VOCs), chlorinated solvents, and metals. PCBs were not detected in any of the soil and groundwater samples analyzed. Despite minimal human-health risks associated with residual contamination, consideration was given to in-place treatment or removal of “source” soils in the vicinity of the service area sump, wash rack, and loading dock dry well to reduce concentrations of detected contaminants in those areas. Detected contaminants in those areas represent an environmental liability for the subject property associated with future facility improvements (e.g., future soil excavation associated with subsurface and near-surface utility and infrastructure construction projects), apart from regulatory review and opinion. Upon completion of a Feasibility Analysis, which evaluated four (4) potential remedial alternatives for contaminant reduction in source areas, the potential data gaps and/or areas requiring additional characterization were recognized near the service shop sump, near the wash rack, and in the north portion of the site near several push probes.

In addition to the data gaps associated with these areas, new information was provided following completion of the focused Phase II ESA that identified the location of former PCB containing transformers at the subject property. This area, and other areas of concern to the potential buyer, were then added to the scope of an expanded Phase II ESA of the subject property. In early 2008, 17 additional push-probe borings were installed at the subject property. As part of the expanded investigation, soil samples were collected from each of the soil borings. Groundwater samples were collected from 10 of 17 push probe borings as agreed upon by the potential buyer. As further quantified by completion of the expanded Phase II ESA, the subject property has apparently been impacted by leaking infrastructure associated with disposal sumps (north shop area), a diesel spill, and improper handling, management and control of petroleum products and petroleum waste. Contaminants in soil appeared to be limited to primarily diesel-range and heavy oil-range TPH. Low concentrations of a few TPH related VOCs, tetrachloroethene (PCE), and PAH compounds were also identified.

Groundwater contamination appeared to be limited to diesel-range TPH, heavy oil-range TPH, and PAHs west and northwest of the service shop, presumably associated with dry well storm sewer system infiltration in this portion of the subject property. Minimal VOC and PCE contamination was detected in groundwater in this area. However, low levels of PCE in groundwater appear to extend over much of the south and southwestern portions of the site beneath the footprint of the former pipe manufacturing building.

To evaluate potential environmental liability and human-health risk posed by detected contamination in soil and groundwater, documented contaminant concentrations were compared to the risk-based concentrations (RBCs) developed by the Oregon Department of Environmental Quality (DEQ) in the guidance document titled Risk-Based Decision Making (RBDM) for the Remediation of Petroleum-Contaminated Sites. Where RBCs were not available, EPA’s Region 9 Preliminary Remediation Goals (PRGs) were used as reference levels. Based on current and likely future land use and zoning of the subject property, appropriate non-residential RBCs were used for potentially complete exposure pathways and receptor scenarios.

A site history review was performed and included compilation and evaluation of available public information including property deed records, permit filings, aerial photographs, and city directories. The review of this information identified two (2) former gasoline service stations and two (2) former dry cleaning facilities on the subject property. The site history review also identified four (4) former gasoline service stations, two (2) former dry cleaning facilities, and a former truck sales and service facility in the area surrounding the subject property.

A government agency list review was also performed and included a search of public information related to the documented use and management of hazardous chemicals and wastes and/or reported releases to the environment. The subject property was identified by the Oregon Department of Environmental Quality (DEQ) as a conditionally exempt generator of hazardous waste, as a registered UST facility, and as a leaking underground storage tank (LUST) site. The on-site service stations and dry cleaning facilities were not identified during the government agency list review.

A site survey was performed and focused on exterior features of the site that may be related to potential environmental liabilities, including: 1) soil staining and/or stressed vegetation; 2) the presence of hazardous materials on the property or on neighboring properties; and 3) any other conditions relative to the presence of material which may present an environmental liability. The site inspection identified conditions (i.e., sunken asphalt, possible fill ports) at one of the two (2) former gasoline service station sites located on-site that suggested the USTs may still be present. No obvious indications of the other former gasoline service station or the two (2) former dry cleaner facilities located on-site were observed during the site inspection.

Based on the findings of the Phase I ESA, two (2) specific areas were recommended for further investigation (i.e., Phase II ESA). The area identified as Site #1 included the former gasoline service station site with sunken asphalt and possible fill ports. The area identified as Site #2 included the other former gasoline service station site and one (1) former dry cleaner site. The remaining former dry cleaning site was inaccessible due to current building facilities.

Further investigation of Site #1 discovered two (2) abandoned USTs. One (1) empty 1,000-gallon UST and one (1) 500-gallon UST containing toxicity characteristic hazardous waste. The collection of soil and groundwater samples for laboratory analysis confirmed the presence of gasoline- and lube oil-range petroleum hydrocarbon impact. The two (2) USTs were subsequently decommissioned by removal.

Groundwater sampling at Site #2 detected volatile organic compounds (VOCs) commonly associated with dry cleaning operations in the groundwater beneath the site at concentrations in excess of the Environmental Protection Agency (EPA) drinking water maximum contaminant levels (MCLs). Based on the results of the Phase II ESA, additional investigation was recommended to further characterize the lateral extent of the VOC impact.

The results of the Phase I ESA identified several recognized environmental conditions including an on-site release of alcohol from a former underground storage tank (UST), former use of chemicals such as tetrachloroethylene (PCE), 1,1,1-trichloroethane (TCE), isopropyl alcohol, methanol, ethanol, and PCE-containing solutions in on-site operations, and area wide presence of trichloroethene (TCE) groundwater contamination. Based on the results of the Phase I ESA, and to limit potential future liability, BB&A Environmental recommended that background levels (if any) of contaminants in soil and groundwater beneath the property be investigated prior to acquisition of the property. A subsequent Phase II ESA conducted at the site, which included completion of five (5) push probe borings to facilitate sample collection, detected PCE, TCE, and related break-down compounds in groundwater at levels exceeding US Environmental Protection Agency (EPA) Preliminary Remediation Goals (PRGs) and Maximum Contaminant Levels (MCL) for drinking water. Although the sale of the property occurred, the former facility owner was identified as the responsible party for future cleanup.

The Risk-Based Corrective Action Plan (CAP) included completion of a conceptual site model (CSM). The CSM identified an occupational and excavation and construction worker receptor scenarios for the site and the following exposure pathways were deemed complete for both soil and groundwater including: vapor intrusion to indoor air and volatilization to outdoor air exposure pathways. TPH as gasoline and several gasoline constituents including benzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, naphthalene, and total xylenes were identified as contaminants of concern (COC). Transition of ozone injection to Phase II wells began when dissolved groundwater contaminant concentrations in monitoring wells in the area of the building were below the generic occupational and excavation and construction worker RBCs for vapor intrusion to indoor air and volatilization to outdoor air exposure pathways.

In 1991, two (2) independently operated groundwater pump-and-treat systems were installed to process groundwater impacted by the release and control plume migration. Although considered the most appropriate remediation option at the time, pump-and-treat techniques are considered less effective in low yielding aquifers characterized by high silt- and clay-rich soils such as are present beneath the site. Beginning in 1995, BB&A Environmental conducted a series of investigations to evaluate the effectiveness of several alternate remediation options to accelerate the rate of remediation. These options included air sparging, soil vapor extraction (SVE), dual-phase extraction, and bioremediation.

In November 1995, BB&A Environmental conducted a pilot study to evaluate the potential for implementing SVE techniques at the site. A vacuum of 45 inches of water was applied to a SVE well. Measurements of the exhaust gases confirmed the presence of combustible gases at concentrations ranging up to three (3) percent of the lower explosive limit (LEL) of gasoline. Results of the test generally indicated that SVE may be feasible remedial technology.

In 1997, a feasibility study was performed to evaluate the potential for effective implementation of air sparging and SVE techniques for site remediation. Air sparging is process in which compressed air is introduced below the water table. Air sparging benefits the remediation process two (2) ways. First, the introduction of compressed air promotes the volatilization of sorbed-phase petroleum hydrocarbons which can subsequently be recovered by a secondary mechanical system (e.g., SVE). Secondly, air sparging increases the level of dissolved oxygen (DO) in groundwater which can promote in-situ (i.e., in-place) biodegradation.

The air sparging feasibility study included six (6) air sparging points placed around an existing monitoring well. An off-site groundwater monitoring well was used as a control monitoring point. Groundwater samples were collected from the observation and control wells to establish baseline concentrations of dissolved benzene, toluene, ethylbenzene, xylene (BTEX), DO, biological oxygen demand (BOD), and aerobic hydrocarbon degrading bacteria. The wells were sampled periodically throughout the sparging study to monitor responses in groundwater quality.

Reductions in benzene (approximately 15%), toluene (approximately 30 to 50%), ethylbenzene (approximately 27%), and xylene (approximately 12 to 20%) were documented in the test well relative to baseline values. Levels of DO increased by approximately 260 percent relative to baseline values. Levels of BOD and aerobic bacteria plate counts decreased by approximately 18 and 45 percent, respectively, during the study.

Based on the findings of the feasibility studies, BB&A Environmental installed an SVE and air sparging system at the subject property in February 1999. The system consisted of 26 SVE points and 24 air sparging points.

In August 2000, BB&A Environmental conducted a study to determine the potential for biodegradation within the groundwater contaminant plume. Baseline levels of DO, dissolved iron, sulfate, and nitrate were determined at one (1) well located outside the groundwater contaminant plume and five (5) wells within the groundwater contaminant plume. The study identified decreased DO levels within the perimeter of the plume and concluded that these levels could not support aerobic degradation of organic compounds. Furthermore, alternative electron acceptors (e.g., NO3-, SO42-) were absent within the groundwater contaminant plume which indicated minimal potential for future anaerobic degradation. The study concluded that increased airflow in unsaturated soils and/or the introduction of dissolved oxygen within the groundwater contaminant plume would be required to promote biostimulation.

In August 2000, BB&A Environmental installed a dual-phase remediation system designed to recover soil and groundwater contaminants from beneath an impacted portion of the adjacent off-site property. Dual-phase remediation uses vacuum-enhanced recovery techniques to simultaneously recover soil vapor and groundwater from single or multiple recovery wells. Vacuum-enhanced recovery techniques are well suited in hydrogeologic environments characterized by low permeability soils and low transmissivity aquifers such as are encountered at the project site. In these environments, the application of mechanical vacuum techniques can increase the rate of horizontal groundwater movement within the aquifer thus enhancing the rate of groundwater production relative to “conventional” pump-and-treat systems. In addition, use of dual-phase extraction techniques can increase the effective porosity of the soil matrix by removing pore moisture present in “unsaturated” soils. The removal of pore moisture results in higher airflow rates and more effective recovery of vapor-phase contaminants.

The dual-phase remediation system consists of two (2) 15-horsepower liquid ring pumps connected to 20 remediation wells. Groundwater recovered by the dual-phase extraction system is processed using air-stripping techniques. The rate of groundwater production from the dual-phase extraction system is up to seven (7) times higher than groundwater recovery rates from conventional pump-and-treat techniques. Furthermore, aggressive groundwater recovery methods result in higher levels of dissolved contaminants in groundwater recovered by the dual-phase extraction system.

In January 2001, BB&A Environmental installed a liquid propane gas-fired catalytic oxidizer to process soil vapor recovered by the dual-phase extraction system. The catalytic oxidizer converts vapor-phase petroleum hydrocarbons into more stable, fully oxidized compounds of carbon and hydrogen (i.e., CO2 and H2O) through the process of chemical oxidation. Operation of the catalytic oxidizer reduces petroleum hydrocarbon emissions by more than 99 percent.

Confirmation soil samples collected from remaining PCS in the excavation zone contained diesel-range total petroleum hydrocarbon (TPH) concentrations as high as 20,000 mg/Kg. Based on analytical results of additional soil samples, PCS extended laterally beneath the garage of the residence and off-site. BB&A Environmental recommended a risk-based approach to closing the site. To this end, BB&A Environmental undertook the following investigative actions:

• Delineation of the vertical and lateral extent of soil impact through the completion of push probes on- and off-site to allow the collection of soil samples
• Development of a conceptual side model (CSM) which identified contaminants of concern (COC) present at the site, and selection of potential exposure pathways and potential receptors at the site
• Comparison of exposure pathways and potential receptors selected by the CSM to COC identified benzene at levels above the generic risk-based concentrations (RBCs) for both leaching to groundwater and vapor intrusion into buildings exposure pathways

• Further evaluation of the leaching to groundwater exposure pathway was undertaken by recalculating the equation used to determine the generic RBC using a smaller area of soil impact. The recalculated RBC resulted in a site specific benzene RBC above that of the level of benzene present in soils at the site. Because the highest concentration of benzene detected in soils either on- or off-site was less than the recalculated site specific RBC, the remaining concentration of benzene was deemed protective of groundwater
• Further evaluation of the vapor intrusion into buildings exposure pathway was performed by calculating the 90% upper confidence limit (UCL) of the mean for benzene from confirmation soil samples collected from the excavation zone. Using the 90% UCL of the mean, a 30-year mass averaging calculation for benzene vapor was performed, resulting in a benzene level below the residential indoor air inhalation RBC. Therefore, remaining benzene in soils beneath the site which may volatilize into the indoor air space of the residence was determined not to present a risk to human health
• Reporting all findings of the investigation in a Risk-Based Cleanup Report and certification by BB&A Environmental that the work performed met the appropriate requirements of heating oil tank rules in Oregon. After receiving the contractor certification statement, the Oregon Department of Environmental Quality (DEQ) issued a “Heating Oil Tank File Closure Letter” indicating that the DEQ accepted the certification and closed its file for the site

To this end, BB&A Environmental undertook the following investigative actions:

• Delineation of the vertical and lateral extent of soil impact through the installation of soil probes to allow collection of soil and groundwater samples
• Determination of remaining concentrations of contaminants of concern (COC) through constituent based, or compound specific, laboratory analysis
• Development of a conceptual site model (CSM) and determination of potential exposure pathways and potential receptors at the site
• Evaluation of the degree of impact from COC through a comparison of compound specific results with the risk-based concentration (RBCs) listed Risk-Based Decision-Making for Remediation of Petroleum Contaminated Sites
• Reporting all findings of the investigation in a corrective action plan (CAP) to be submitted to the Oregon Department of Environmental Quality (DEQ) for approval and issuance of a “no further action” (NFA) or site closure letter

Having completed these investigative and reporting tasks, BB&A Environmental successfully obtained on behalf of the client regulatory site closure and issuance of an NFA determination from the DEQ.

At various sites, BB&A Environmental installed and successfully operated remediation systems which have employed soil vapor extraction (SVE), air-sparging, groundwater pump-and-treat and dual phase liquid/vapor extraction technology. Achievement of final cleanup at several sites was accelerated with completion of risk assessments including the development of conceptual site models (CSM) and use of risk based concentration (RBC) standards. By thoroughly evaluating the potential exposure pathways at these sites, BB&A Environmental demonstrated that less stringent cleanup goals were acceptable and met the Oregon Department of Environmental Quality (DEQ’s) requirements for regulatory closure and issuance of “no further action” (NFA) determinations.

Treatment was performed by passing extracted fluids through a coalescing plate oil-water separator, a tray-aeration air stripper, and three (3) carbon canisters. The treated groundwater was discharged into the adjacent Willamette River under the Oregon Department of Environmental Quality (DEQ) National Pollutant Discharge Elimination System (NPDES) 1500A Permit.

Remediation efforts were expanded to the shoreline of the Willamette River after consultation with the DEQ, Oregon Division of State Lands, US Army Corps of Engineers, and the City of Portland. Expanded remedial efforts included installation of a dual-phase extraction (DPE) system replacing the submersible pumps previously installed in recovery wells RW-1 and RW-2 and installation of an air-sparging system including installation of 19 air-sparging wells in the beach area adjacent to the Willamette River.

Groundwater monitoring data indicated that operation of the in-situ remediation system resulted in achievement of target cleanup standards. Following a period of compliance groundwater monitoring, the site was issued a “no further action” (NFA) determination by the DEQ.

Due to changes in material handling at a log deck and sawmill, disposal of wood waste and related materials at the landfill was no longer needed and BB&A Environmental subsequently assisted the permittee in negotiating regulatory closure of the site. Through evaluation of historical monitoring data, BB&A Environmental was successful in obtaining regulatory concurrence with termination of groundwater monitoring and reporting activities under the closure permit issued for the site.

As outlined below, BB&A Environmental has assisted Coos County with preparation of sampling and analysis plans, data evaluation, report preparation and undertaken investigative and corrective actions on behalf of the County in response to contaminant releases to the environment. Specific services BB&A Environmental has provided at the three (3) Coos County disposal sites since 1994 have included:

• Preparation and execution of work plans for site characterization, Preliminary Assessment and Preventative Action (PA), and Expanded Preliminary Assessment (XPA)
• Preparation of Annual Environmental Monitoring Reports (AEMRs)
• Preparation and update of Environmental Monitoring Plans (EMPs)
• Closure of former leachate storage pond and irrigation spray field
• Completion of Supplemental Environmental Project (SEP) involving acquisition and testing of dedicated low flow purging and sampling equipment
• Preparation of Scrubber Residue and Incinerator Residual Management Plans, emergency leachate management plan, and landfill gas monitoring plan
• Modification of monitoring networks/installation of groundwater monitoring wells
• Waste Determinations
• Preparation of technical specifications for bidding documents

BB&A Environmental performed a rigorous validation and statistical analysis of monitoring data that supported elimination of certain monitoring parameters and a reduction in monitoring frequency which achieved a 50 percent reduction in environmental monitoring costs. The County also retained BB&A Environmental to assist with negotiating the scope of Remedial Investigation/Feasibility Studies (RI/FS), which when completed are expected to result in further reduction in monitoring expenses. BB&A Environmental also assisted Coos County with implementation of a process change involving the incinerator air pollution control equipment at the Beaver Hill site that eliminated generation of approximately 600 tons per year of hazardous waste; the County is now able to dispose of this material in the on-site fully lined ash monofil and eliminate costly off-site disposal of the material as hazardous waste.

Initial characterization of the contamination indicated that residual volatile organic compounds (VOCs) were present in soil in excess of applicable risk-based concentrations (RBCs) for a residential receptor scenario. Groundwater impact did not exceed applicable RBCs. Following demolition of existing structures, a geophysical subsurface survey confirmed the presence of three (3) remaining underground storage tanks (USTs). The USTs were decommissioned by removal and soil containing elevated levels of residual total petroleum hydrocarbons (TPH) and associated VOCs was removed for off-site disposal. Residual TPH impacted soils were treated in situ using soil vapor extraction remedial technology. BB&A Environmental identified impacted soils requiring off-site disposal that resulted from foundation excavations, geothermal well installations, and the drilling of an elevator shaft. BB&A Environmental worked with the architect on design changes to limit disrupting impacted soil and prepared documentation of excavation/boring locations and final disposal of the impacted soil. The magnitude and extent of off-site soil and groundwater impact was delineated using push probe sampling technology.

Groundwater beneath the site was monitored during high and low groundwater table conditions using the network of seven (7) groundwater monitoring wells. Upon completion of the in situ soil treatment, final confirmation soil samples were collected for analysis. The Oregon Department of Environmental Quality (DEQ) issued a “no further action” (NFA) determination 11 months after the start of the cleanup activities.

A Phase II Environmental Site Assessment (ESA) confirmed the presence of total petroleum hydrocarbon (TPH) in soil and the presence of chlorinated volatile organic compounds (VOCs) in the groundwater. BB&A Environmental delineated the magnitude and extent of soil and groundwater impact and developed a site remediation plan to be implemented as part of site construction activities. The City of Eugene entered into a voluntary cleanup agreement with the Oregon Department of Environmental (DEQ) for oversight and approval of the remedial action plan. BB&A Environmental worked with the prime contractor and the earth work subcontractor to develop a plan to properly handle TPH impacted soil that would be removed during site excavation activities. The majority of the soil impact had to be removed as part of the basement excavation planned for the new library. BB&A Environmental provided oversight to identify the area of soil impact requiring off-site treatment at a DEQ permitted facility, documented the area and quantity of TPH impacted soil, and collected confirmation soil samples to document conditions of soils not requiring excavation associated with development of the new library.

In order to meet geotechnical requirements of the new library, the excavation activities extended below the water table level in some areas. BB&A Environmental designed a groundwater treatment system to treat contaminated groundwater during the excavation de-watering activities and basement construction. BB&A Environmental performed an off-site investigation to confirm that groundwater impact was the result of off-site activities and the DEQ has concurred that the City of Eugene would not have to address the off-site contamination.

To most efficiently address specific environmental concerns and issues associated with these various areas of the Riverfront Research Park, the property was separated into several separate parcels. Since 1994, BB&A Environmental has assisted the University of Oregon with completion of extensive investigative and cleanup activities at the site to allow for progressive development. Specific activities have involved preparation and execution of work plans approved by the Oregon Department of Environmental Quality (DEQ), collection and analysis of soil, groundwater, sediment, and pore water samples, installation and quarterly monitoring of permanent groundwater wells, waste determinations, risk assessments, and preparation of reports documenting such activities. As a result, the DEQ issued written “no further action” (NFA) determinations for all but one (1) area of one (1) parcel that is contiguous with the “core area” and primary operational facilities associated with the former Eugene Manufactured Gas Plant which is owned by the Eugene Water and Electric Board (EWEB). BB&A Environmental prepared a report for this parcel that recommends regulatory closure in accordance with Oregon Revised Statutes (ORS) 465.200 et. seq. and Oregon Administrative Rules (OAR) Chapter 340, Division 122, Sections 010 through 115.

At the time of the Focused Site Assessment, the subject property was surrounded by a six (6) foot perimeter fence and locked gates. The former operations building had been reduced to the exterior concrete tilt-up walls, the concrete slab floor, and the wood-beam supporting roof. The former concrete dip tanks in the operations area were reportedly razed, the spoils of which were placed in several piles within the operations building and on the southernmost portion of the property. Also observed in the operations area was the former metal rails hanging from the roof and concrete trenches in the concrete slab of the operations building. Various refuse and debris was scattered throughout the operations area and office space. The Focused Site Assessment included: sampling and laboratory analysis of sediment and stormwater in the storm sewer system; sampling and analysis of various piles of concrete rubble; and sampling and analysis of soil and/or groundwater from 18 push probe borings.

The results of the assessment detected diesel-range total petroleum hydrocarbons (TPH) and heavy oil-range TPH in shallow soils in the south-central operations area and northeast of the former trichloroethene (TCE) tank. Additionally, soils were found to contain tetrachloroethene (PCE), various polynuclear aromatic hydrocarbon (PAH) compounds, various metals, and cyanide. In groundwater, the assessment confirmed concentrations of TCE and cis-1,2-Dichloroethene (cis-DCE). In the deeper groundwater samples, cis-DCE, 1,1-Dichloroethane (1,1-DCA), and vinyl chloride were detected. After completion of the assessment, the property was purchased through a Prospective Purchaser Agreement (PPA) with the DEQ.

Reporting has included determination of groundwater flow direction and gradient, evaluation of time-concentration variation of water quality monitoring parameters, and evaluation of potential sources of nitrate impact documented in the uppermost aquifer. Based on historical groundwater monitoring data, influent nitrate concentrations, groundwater flow direction and gradient, and land use in the area, BB&A Environmental concluded that operation of the wastewater lagoon has not resulted in increased nitrate concentrations documented during quarterly groundwater monitoring events.