Summary of Proposed West Linn Solar Highway Project Site

Summary of Proposed West Linn Solar Highway Project Site Feasibil ity Analysis

Prepared for the Oregon Department of Transportation Off ice of Innovative Partnerships March 2010 Good Company Eugene, Oregon

Summary of Proposed West Linn Solar Highway Project Site Feasibility Analysis 1

Table of Contents Project Overview ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Site Description and Affected Project Area ....................................................................................... 3

ODOT Environmental Review Process .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Overview of the NEPA Process ........................................................................................................... 6 Known Significant Impacts Require an Environmental Impact Statement..................................... 7 Unknown Significant Impacts Require an Environmental Assessment........................................... 7 No Significant Impacts Require a Categorical Exclusion.................................................................. 8 West Linn Solar Highway Project Will Result in No Significant Impacts .......................................... 8 Additional Resources .......................................................................................................................... 9

Public Involvement .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 West Linn Public Involvement Activities ............................................................................................ 9 Electromagnetic Fields and Human Health.....................................................................................10 Life-Cycle Environmental and Human Health Hazards...................................................................11 Potential for Increased Wildfire Risk................................................................................................11 Potential for Increased Crime and Vandalism.................................................................................12 Potential for Glare from the Solar Panels........................................................................................12

Biological Resources .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Biology Baseline Report ....................................................................................................................13 Botanical Resources .........................................................................................................................13 Wildlife Resources.............................................................................................................................14 Aquatic Resources ............................................................................................................................14 Wildlife Corridors and Linkages .......................................................................................................14 No Significant Effect to Biological Resources .................................................................................15 Additional Resources ........................................................................................................................15

Water Resources .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Wetland and Waters Delineation Report .........................................................................................16 Wetland Resource Delineation and Jurisdiction .............................................................................16 Water Resource Delineation and Jurisdiction .................................................................................19 Stormwater Drainage Report............................................................................................................19 No Significant Effect to Water Resources .......................................................................................20 Additional Resources ........................................................................................................................20

Land Use ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Existing Conditions ............................................................................................................................21 Additional Resources ........................................................................................................................23

Hazardous Materials .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 No Significant Effect from Hazardous Materials.............................................................................24 Additional Resources ........................................................................................................................24

Noise .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Noise Analysis....................................................................................................................................25 Potential Noise Impacts of Solar Power Inverters...........................................................................25 Tree Removal Potential Noise Impacts............................................................................................25 No Clearly Noticeable Increase in Noise Levels..............................................................................26 Additional Resources ........................................................................................................................26

Visual and Aesthetic Resources .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Visual Resource Report ....................................................................................................................27


Existing conditions ............................................................................................................................27 Potential Effects to the Barrington Heights Viewshed....................................................................27 Potential Effects to the Canemah Bluff Viewshed ..........................................................................28 No Significant Effect to Visual Resources .......................................................................................29 Additional Resources ........................................................................................................................29

Socioeconomic .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Community Cohesion and Economic Vitality ...................................................................................30 Environmental Justice.......................................................................................................................30

Geotechnical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Geotechnical Report .........................................................................................................................31 Existing Conditions ............................................................................................................................31 Potential Impacts from the Proposed Project .................................................................................31 No Significant Effect to Slope Stability ............................................................................................32 Additional Resources ........................................................................................................................32

Air Resources .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Potential Impacts to Air Quality ........................................................................................................32 No Significant Effect to Air Resources .............................................................................................32

Archaeological and Historic Resources .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 No Significant Effect to Archaeological Resources .........................................................................33 No Significant Effect to Historic Resources.....................................................................................33 Additional Resources ........................................................................................................................33

Environmental Commitments .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Additional Resources ........................................................................................................................35


Project Overview The Oregon Department of Transportation (ODOT) has proposed to enter an agreement with Portland General Electric (PGE) to develop a 3-megawatt (MW) photovoltaic (PV) solar array at an operations and maintenance storage yard at milepost 6.9 adjacent to Interstate-205 (I-205) in West Linn, Clackamas County, Oregon. The proposed West Linn Solar Highway project would consist of the installation of approximately 13,000 230-watt PV modules and ten 260-kilowatt (kW) inverters. The project would be capable of producing up to 3,500 megawatt-hours (MWh) of electricity per year. Electricity generated at the site would offset a portion of ODOT’s electricity load in the PGE service area. The annual output of the project would be enough to supply approximately 18% of ODOT's electricity needs in the service area. In addition to the panel installation, the project would also entail construction of gravel roads for maintenance and emergency vehicle access, stormwater conveyance improvements, construction of security fencing and interconnections of the facility with PGE's existing distribution grid. Site Description and Affected Project Area The proposed location for the project is an approximately 47-acre area of ODOT owned highway right-of-way north of I-205 and west of S. Salamo Road in West Linn, Oregon. The footprint of the proposed project is approximately 13 acres. The project location and footprint are shown on the map in Figure 1 on page 5. The site is on a south-facing slope that features two terraced benches that rise above I-205 and a narrower third bench toward the north of the site. The proposed solar array would be sited on the two lower benches. The site is bound to the east and west by the drainages of intermittent streams. To the north the ODOT property adjoins a residential neighborhood, Barrington Heights. The terraced benches were created in 1969 during the construction of I-205 to stabilize the slope and protect the highway from landslides. The lower bench is currently utilized by ODOT as an equipment and material storage yard and construction staging area for nearby road and bridge improvement projects. The only vehicular access to the site is from southbound I-205 via an unpaved gravel drive. The remainder of the site has been left largely undisturbed since the construction of I-205 allowing small stands of trees to grow along the benches. Most of the site though consists of dry grasslands dominated by non-native grasses and forbs. The site also features several small wetlands primarily in low-lying ditches along I-205. The area immediately adjacent to the project area is characterized by suburban and industrial land uses. In addition to the residential neighborhood to the north, the area


nearby the project site features a municipal wastewater treatment facility and a school bus storage yard to the south and a decommissioned highway rest area to the east. The Willamette River is located approximately a quarter mile south of the project area and the Willamette Falls Dam and Locks are located approximately one-mile downstream. In the larger context, the site is located within the Willamette Narrows-- a reach of the river and valley constrained by rocky bluffs and rolling hills. The Canemah Bluff Natural Area south of the project location and across the Willamette River in Oregon City is representative of high-quality white oak woodland and savanna habitat characteristic of minimally disturbed or developed area within the narrows.

Summary of Environmental Review Process for Proposed West Linn Solar Highway Project 5

Figure1: Poject map


ODOT Environmental Review Process The Oregon Department of Transportation is committed to the protection and preservation of our state's unique environment and is required to comply with a host of federal, state and local environmental and land use laws in all of its projects and activities. Many state transportation projects involve federal funds or impact a federal resource like an interstate highway interchange, triggering the environmental review process required by the National Environmental Policy Act (NEPA). The NEPA process is designed so that public officials consider and document the potential environmental consequences of their proposals and pursue solutions that meet the project need while protecting, restoring, and enhancing the environment. For projects involving Federal Highway Administration (FHWA) funds or approvals, ODOT usually participates as a joint lead agency with FHWA. Accordingly, ODOT's staff of technical experts and specialists typically is responsible coordinating the majority of the environmental analysis for a given project. ODOT has established guidance and procedures, approved by FHWA, which it follows for the preparation of documents in order to be sure that all of the relevant statutes and rules are followed. The NEPA process is also frequently used as a framework to ensure compliance with the requirements set forth in other federal, state and local environmental protection laws and regulations including but not limited to the Clean Water Act and the Endangered Species Act. It is ODOT’s practice to apply the NEPA process to projects that involve ground-disturbing or physical impacts, even if the project does not involve the use of federal funds or otherwise meet the definition of major federal action. Consistent with this practice, ODOT has followed the environmental due diligence process called for under NEPA in evaluating the feasibility and suitability of the proposed West Linn Solar Highway project. Overview of the NEPA Process The first step in any NEPA process is to make a determination based on an initial evaluation of the facts as to whether a proposed project would individually or cumulatively have a significant impact on the human environment or involve other unusual circumstances. The determination of significance is a function of both context and intensity that is, the severity of the impacts in light of the type, quality and location of the resource involved. The NEPA process considers potential direct, indirect, and temporary impacts for foreseeable actions; remote and speculative impacts are not considered during the NEPA process. Figure 2 (below) shows three pathways for the determination of significance of impacts.


Figure 2: NEPA Process Flowchart

Known Significant Impacts Require an Environmental Impact Statement If the proposed project is known or believed to have a significant impact, the agency must prepare an Environmental Impact Statement (EIS). The EIS process actually involves several steps including notification in the Federal Register, a public process to identify the important issues to consider and analyze, the preparation of a draft EIS, a public comment period to solicit feedback on the draft EIS, the preparation of a final EIS and the issuance of a Record of Decision indicating the selected course of action. A major realignment of a highway, a new interstate bridge over a river or the construction of a new highway in a natural area are examples of the types of projects that typically require an FHWA EIS. Unknown Significant Impacts Require an Environmental Assessment If the agency is uncertain if the proposed project would result in a significant impact, the agency must prepare an Environmental Assessment (EA). The purpose of the EA is to evaluate the significance of a proposed project and to consider alternative means to achieve the agency's objectives. If the agency discovers at any point in the process of preparing an EA that the project would result in significant impacts as defined by 40 CFR 1508.27, then an EIS process must be followed. If the agency does not discover any significant impacts after completing the EA and after considering public or


interagency comments, then it may issue a finding of no significant impact (FONSI) and the agency project can proceed. No Significant Impacts Require a Categorical Exclusion If the proposed project would not have significant environmental impact the project may be classified as a Categorical Exclusion or CE, also known as Cat Ex. The FHWA divides CEs into two groups, standard and documented, based on the proposed project’s potential for impacts. A standard CE may be issued automatically by the FHWA for certain types of activities that previous experience has shown to rarely result in significant environmental impacts. A list of specific activities typically granted a standard CE is set forth in federal regulations at 23 CFR 771.117(c) and include minor construction activities and administrative actions. A documented CE may be issued by the FHWA if supporting analysis and appropriate documentation confirms that the proposed project does not involve significant impacts. Examples of the type of activities that require a documented CE are also described in federal regulations at 23 CFR 771.117(d). Activities of a similar type and scope to those listed in FHWA’s NEPA implementing regulations may also be classified as a documented CE. It is possible that a project initially classified as a CE could become subject to further review in an EA or EIS. If the CE documentation is inconclusive and the likelihood of significant impacts is uncertain, then an EA must be prepared. If the analysis finds that the project would result in significant impacts, then the EIS process must be followed. However, if the documentation confirms that no significant impacts are likely to occur, then the CE process and documentation is completed and the agency project can proceed. West Linn Solar Highway Project Will Result in No Significant Impacts The proposed West Linn Solar Highway Project was initially classified as a NEPA CE project. Based on additional ODOT-led environmental analysis it remains ODOT's assessment that there will be no significant impacts on urban, community, natural or physical resources resulting from the proposed West Linn Solar Highway Project. In preparing the analysis that demonstrates that the proposed project will not result in significant environmental effects, ODOT examined a range of environmental topics including: biological resources and threatened and endangered species, wetland and water quality issues, the applicability of state and local land use regulations, hazardous materials, noise, visual and aesthetic resources, socioeconomics, geotechnical, air quality and archaeological, historical and cultural resources.


ODOT also investigated other issues of concern raised by the public including potential adverse human health effects related to electromagnetic fields associated with the project, the potential environmental and health hazards associated with the life cycle of solar photovoltaic solar panels, the potential for increased wildfire risk resulting from the project, the potential for increased incidents of crime and vandalism in the surrounding area and the potential for glare from the solar panels. A summary of this analysis follows in the subsequent sections of this document. Additional Resources For general information about NEPA read The Council on Environmental Quality's A Citizen’s Guide to the NEPA at http://ceq.hss.doe.gov/nepa/Citizens_Guide_Dec07.pdf. For more information about environmental review and NEPA implementation at the FHWA visit http://www.environment.fhwa.dot.gov/index.asp. For information about ODOT's role in NEPA, see the ODOT NEPA Coordination web page at: http://www.oregon.gov/ODOT/HWY/GEOENVIRONMENTAL/nepa.shtml. Public Involvement A cornerstone of the NEPA process is to provide citizens and stakeholders an opportunity to participate in agency decision-making. Public involvement in agency decision-making helps to ensure that all relevant potential impacts are considered. Often the public has insight and expertise that can lead to the avoidance or minimization of adverse impacts. Depending on the level of public interest and the scope and scale of a project, the NEPA process requires different levels of public involvement and review. More complex projects that require the preparation of environmental assessments or environmental impact statements are required to have additional formal opportunities for the public to comment on these documents and to weigh-in on a proposed project during one or more formal public meetings. At a minimum, ODOT seeks to inform the public and solicit their feedback during the initial phases of a project. West Linn Public Involvement Activities For the proposed West Linn project, ODOT collaborated with the City of West Linn to design and conduct a number of public involvement activities. Specifically, ODOT and the City of West Linn conducted over forty-two different outreach activities including: • Mailings to and meetings with community stakeholders;

• Working with local media outlets to ensure coverage of the project;


• Meetings with residents and neighborhood associations;

• Creation of a discussion forum on the City of West Linn's website;

• Regular email communication with subscribers to the City of West Linn's distribution

list;

• Printed and electronic notice of informational meetings;

• Three public informational meetings, two in West Linn and one in Oregon City;

• Project presentations and accepting public comments at Oregon City and City of

West Linn Council meetings;

• A site visit to the homes of residents in Oregon City with views of the proposed

project site;

• A tour of the project site with select citizens and elected and public officials;

• Two newsletter mailings to residents of Barrington Heights Neighborhood;

• A presentation to Barrington Heights Association of Homeowners; and,

• Email exchanges with interested citizens, city staff, and elected officials in response

to specific questions and concerns.

During this extensive public involvement process, community members raised a number of concerns as noted previously. These included the potential of adverse human health effects related to electromagnetic fields associated with the project, the potential environmental and health hazards associated with the life cycle of solar photovoltaic solar panels, the potential for increased wildfire risk resulting from the project, the potential for increased incidents of crime and vandalism in the surrounding area and the potential for glare from the solar panels. ODOT responded to these concerns by commissioning supplemental evaluations and soliciting the opinion of relevant issue experts. ODOT made the responses available through its program website, postings to the City of West Linn's web-based discussion forum and by electronic distribution to community stakeholders upon request. Electromagnetic Fields and Human Health On the issue of potential adverse human health effects from electromagnetic fields (EMFs), the review commissioned by ODOT found that the levels of EMFs likely to be produced by the project fall well below the International Commission on Non-Ionizing Radiation Protection guidelines for public exposure and would likely be indistinguishable from background levels produced by other human and natural sources at the perimeter of the site's security fence. Furthermore, the research found that the current scientific consensus is that no causal relationship exists between exposure to low-level power frequency EMFs and any


adverse health effects including childhood cancer. The conclusions of this research are consistent with a review of the issue conducted by the U.S. Department of Energy. Additional information can be obtained at: http://www.oregon.gov/ODOT/HWY/OIPP/docs/solar_USODEmemo.pdf http://www.oregon.gov/ODOT/HWY/OIPP/docs/EMFconcerns.pdf Life-‐Cycle Environmental and Human Health Hazards With regard to potential environmental and human health hazards associated with the life-cycle of solar photovoltaic panels, the additional review commissioned by ODOT found that while potential hazards exist in the upgrading and processing of silica, none present a risk different or greater than the risks found routinely in modern society and that solar photovoltaic panels produce significantly fewer harmful air emissions on a kilowatt-hour basis than conventional fossil fuel fired electricity sources. The research also disclosed reviews conducted by the Brookhaven National Lab and the Electric Power Research Institute concluding that installed silicon-based solar modules pose virtually no risk to human health or the environment. This conclusion is based in large part on the fact that all solar cells are encased in heavy-duty glass or plastic, thereby preventing the release of semiconductor material into the environment. Additional information can be obtained at: http://www.oregon.gov/ODOT/HWY/OIPP/docs/SafetyConcernsPVPanels012510.pdf Potential for Increased Wildfire Risk At the request of ODOT, the Tualatin Valley Fire and Rescue (TVF&R), the designated emergency response agency for the proposed project area, provided a letter addressing community concerns regarding the project's potential to increase wildfire risk. In the letter, TVF&R expressed its opinion that the proposed project may in fact, decrease the risk of wildland fire. The agency draws this conclusion based on its experience that developed properties tend to present lower fire risks than undeveloped properties. Further, the agency stated that the proposed project would decrease fire risk by creating fire breaks that currently do not exist and improve the ability to respond to an emergency incident by providing new access to the site via an extension of the existing gravel drive. Additional information can be obtained at: www.solarhighway.com In addition, ODOT has initiated discussions with the residential neighbors to the north of the project site and other parties with resource restoration interests to see if there is a collaborative solution to reduce invasive, fire-prone plant materials on the site. It is hoped that a public/private solution can be found for a long-term plan to provide improved maintenance and restoration of the upper portion of the site, to further reduce wildfire risk. To read a copy of the letter from Tualatin Valley Fire and Rescue please visit:


http://www.oregon.gov/ODOT/HWY/OIPP/docs/Solar_TVFRopinion.pdf Potential for Increased Crime and Vandalism In the past, a safety rest area, approximately ½ mile to the east of the site, was closed due to high levels of crime and vandalism. Crime and vandalism to the adjoining residential neighborhood were greatly reduced after the rest area was closed. Some nearby residents are concerned that development of the solar highway project will increase the potential for crime and vandalism. Current crime and vandalism at the site includes trespassing and destruction of site vegetation. The proposed solar array will feature a number of security features similar to those at ODOT's existing solar highway project at the I-5 and I-205 interchange near Tualatin. These measures will provide a more robust security presence at the site, compared to existing conditions. As currently designed, the site security features include: • A six foot fence with razor wire; • Motion detection and electrical current interruption sensing equipment; • Security lighting (designed with shielding in accordance with the recommendations of

the International Dark Sky Association); • Cameras; • A 24-hour security response service; and, • “No Trespassing” signage indicating potential penalties Notably, the proposed project will not create a new public access point from I-205. The City of West Linn has started a separate process of determining the feasibility of a new bicycle and pedestrian pathway through the site. While some neighbors are enthusiastic about greater trail connectivity and site access, other neighbors have expressed great concern that a pathway through the site will increase crime and vandalism to the solar array and to their neighborhood adjacent to the site. Due to this concern, the city is evaluating a pathway location that is adjacent to the freeway, south of the fenced array. The City of West Linn's public involvement and approval process for the trail will evaluate potential crime and vandalism impacts of the bicycle and pedestrian trail. Potential for Glare from the Solar Panels A review of concerns related to the reflection of sunlight off the surface of solar panels found that solar panels have a reflectivity of around 30%–similar to the reflectivity of current site surface materials such as dry sand at 45%, needle-leaf coniferous trees at 20%, grass-type vegetation at 25% and broadleaf deciduous trees at 10%. Furthermore the research found that the angle of inclination for the proposed panels would be such that any light reflected from the panels would not cause a glare or reflection for either drivers along I-205 or residents along Canemah Bluff in Oregon City who raised the issue.


Additional information can be obtained at: http://www.oregon.gov/ODOT/HWY/OIPP/docs/Solar_GlarePotentialWL.pdf Biological Resources The construction, operation and maintenance of transportation projects can cause impacts to important natural ecological systems including rare, threatened and endangered species and their habitat. It is recognized that biodiversity plays a critical role in both in natural processes as well as human well-being. Wherever possible, ODOT seeks to avoid impacts to sensitive biological resources. In those circumstances where a proposed project may adversely impact sensitive resources, ODOT develops strategies to avoid, minimize or mitigate these effects. At all times, projects are required to comply with state and federal environmental regulations, including Oregon's and the Federal Endangered Species Acts. Biology Baseline Report It is the responsibility of ODOT's biologists to evaluate a proposed project’s potential to impact sensitive biological resources. This evaluation includes an on-site survey and a review of natural resources databases to assess the type and quality of habitat and document the presence or absence of special status species or their habitat. Special status species include both state and federally listed threatened or endangered species as well as species identified by state, federal or other entities as rare, uncommon or of special interest. The results of this evaluation are presented in a Biology Baseline Report. The Biology Baseline Report for the proposed West Linn Project evaluated the condition and features of the botanical, wildlife and aquatic resources within the project area. The findings and conclusion of the report are outlined below. Botanical Resources According to the Biology Baseline Report, the habitat of the project site is best described as dry grasslands dominated by non-native grasses and forbs. The site also features dispersed stands of trees growing along the upper benches including Douglas-fir, big-leaf maple, black cottonwood, Oregon white-oak, and madrone. Several small wetlands dominated with common wetland species like cattail and watercress are also located within the project area, primarily in low-lying areas along I-205. The number and distribution of the trees were not sufficient to classify any part of the project area as forest or woodland habitat. The composition of the trees did not conform to the characteristics of the native Oak Savanna habitat.


While several special status plant species are known to occur in minimally disturbed areas in the vicinity of the project area, the disturbed nature of the proposed project site has resulted in the replacement of native plant communities with mostly non-native exotics. The site also contains a substantial number of non-native invasive species such as: Himalayan blackberry, scotch broom and Canadian thistle. No special status species were observed within the project area during a plant survey conducted by an ODOT biologist in June 2009. Moreover, the grading activities associated with the creation of the terraced benches and the current composition of flora makes it unlikely that any special status species actually occur on-site. Wildlife Resources Based on the on-site evaluation and a review of available data, the most likely types of wildlife to utilize the project site are common birds and small mammals such as sparrows, red tail hawks and raccoons. The project area's proximity to the I-205 and surrounding residential development limits the likelihood that larger mammals such as bobcat and coyote utilize the site. While some special status species are known to occur in the vicinity of the project area, no special status species were observed at the project site during the ODOT biologist’s on-site survey and no observations of special status species for the site exist in the Oregon Natural Heritage Information Center database, the state's official database of botanical and wildlife observations. The project site does contain some low quality habitat suitable for several special status wildlife species and a nearby resident has observed some special status species at the site over a 14-year period. However, no state or federally protected species are known or expected to occur in the project area nor are any parts of the site designated as critical habitat for threatened or endangered species. It is the conclusion of the ODOT biologist that special status species are unlikely to utilize low quality habitat found within the project area on a regular basis because of the site's disturbed condition and proximity to urbanized land uses. Aquatic Resources Located along the eastern and western edges of the project area are intermittent streams that ultimately connect to the Willamette River. An intermittent stream is a stream in which water flows continuously for only part of the year. While several special status species occur within the Willamette River watershed, the intermittent streams are unlikely to support aquatic reptiles, amphibians or fish species of concern. This conclusion is based on the poor water quality of the streams and the steep slopes of the drainages. Wildlife Corridors and Linkages


While a particular area may not serve as primary habitat it may still provide an important function in a local ecosystem by existing as a wildlife corridor linking higher quality habitats. Fragmented habitats and isolated animal populations can be detrimental to biodiversity. Various regional, state and local entities have recognized the importance of habitat connectivity and have developed conservation strategies to identify, and where possible preserve, important parts of this green infrastructure. In preparing the Biology Baseline Report, the ODOT biologist reviewed wildlife passage issues by reviewing data sets and coordinating with other regional and state agencies. This review revealed that no portion of the project site is within, adjacent or near any state or regionally identified key wildlife corridors. No Significant Effect to Biological Resources Based on the analysis presented in the Biology Baseline Report, an ODOT biologist concluded the proposed project is unlikely to have significant impacts to biological resources. This conclusion is based on the fact that there is no reason to believe that special status species, designated critical habitat or essential fish habitat occurs within the project area. This conclusion does not mean there will be no loss of ecological function associated with the development of the project. The Biology Baseline Report notes that the project does have the potential for small-scale temporary impacts to resident wildlife during construction and may result in some long-term loss of nesting and foraging habitat. Further, construction activities have the potential to spread non-native weed seeds and contribute sedimentation into the eastern and western intermittent streams and eventually fish bearing waterways. Notably, the project has been designed to prevent even these minor impacts by avoiding construction activity within 50 feet of the stream drainages, limiting ground disturbing activities to times outside of migratory bird nesting and breeding periods and requiring weed suppression and native plant restoration. A more detailed discussion of these and other best management practices can be found in the Environmental Commitments section of this document. Additional Resources To obtain a complete copy of the Biology Baseline Report please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Biology_Rpt.pdf Water Resources Healthy communities, economies and ecosystems all rely on safe, clean water. It is the responsibility of ODOT water resource specialists to evaluate the potential impact of a


proposed project to water resources. Water resources include groundwater, rivers, lakes, streams and wetlands. These specialists asses the impact that proposed projects have on water quality and hydrology and help develop measures to protect water resources from adverse effects in order to ensure compliance with local, state and federal regulations, including the Clean Water Act. Wetland and Waters Delineation Report In order to determine if the proposed West Linn Solar Highway project would potentially impact wetlands and surface water resources, ODOT commissioned a Wetland and Waters Delineation Report. The report was prepared by Vigil-Agrimis, Inc. ––a professional services consulting firm specializing in water resources and natural resources planning, analysis and design. The purpose of the report is to identify any wetland and water resources within the project site as well as to identify those water resources outside the project area that could be affected by on-site activities. The authors conducted two on-site field surveys and reviewed applicable geographic information system databases to support the conclusions of the report. Wetland Resource Delineation and Jurisdiction To identify wetland resources the report authors sought to locate those areas within the project site where water occurs at or near the soil surface level together with the presence of wetland plants and soil types. The edge where these conditions ceased to occur together constituted the boundary of the wetland resource. This is the standard scientific method for defining a wetland. The authors identified a total of six wetlands that meet the scientific criteria of a wetland (see Figure 3). However, only four of the six wetlands are considered jurisdictional wetlands. A jurisdictional wetland is a wetland that both meets the scientific criteria of a wetland and is connected to a state or federal water. Jurisdictional wetlands are subject to state and federal removal-fill laws that regulate the placement of fill materials in wetlands. Three of the four jurisdictional wetlands are located in low-lying areas along I-205 below ODOT's existing maintenance and storage yard. The fourth is located at the base of the intermittent stream at the western boundary of the project area. Notably, all of the jurisdictional wetlands are outside of the footprint of the proposed solar array. A review of the delineation report by the Oregon Department of State Lands and the U.S. Army Corps of Engineers concluded that the other two wetlands were non-jurisdictional isolated wetlands because they are not connected to other water or wetland resources by a distinctive surface water connection. Isolated wetlands are not subject to state and federal removal-fill laws. One of the isolated wetlands is located in a low-lying area along I-205 near the western edge of the project area and is outside the footprint of the proposed project.


The other isolated wetland is approximately one-half acre in size and is located along the lower bench just west of ODOT's existing maintenance and storage yard. This isolated wetland would be filled in order to construct the solar array.


Figure 3: Wetland Delineation Map


Water Resource Delineation and Jurisdiction The authors identified other water resources by reviewing appropriate geographic information system databases. The Wetland and Waters Delineation Report identified two waterways within the project area and several others in the vicinity. Both waterways within the project area are unnamed intermittent streams––one along the western end of the project site and the other along the eastern end of the project site. The other water resources in the vicinity include the Willamette River, Tanner Creek and Bernert Creek. The intermittent stream to the west is located in the drainage between the project site and South Salamo Road. The stream flows into a culvert and under I-205 and into the lower Bernert Creek basin. The intermittent stream to the east is located to the east of the existing ODOT maintenance and storage yard and flows into the jurisdictional wetlands below the yard. These waters eventually flow through another culvert and under I-205 and into a detention pond owned by Portland General Electric along the banks of the Willamette River.

Stormwater Drainage Report In order to consider the potential change to stormwater runoff, a concern for nonpoint source pollution impacts, ODOT commissioned a Stormwater Drainage Report. The report was prepared by Parametrix, Inc.––an environmental, planning and civil engineering firm. The purpose of the report was to provide a preliminary analysis of how stormwater drainage patterns might be affected by the proposed project and determine if the proposed project would result in adverse impacts to water quality or floodways. The proposed project will feature several low impact development techniques to manage stormwater runoff (see Figure 4 below). The solar array will be arranged in rows along the existing site terraces with approximately twenty-foot vegetated strips in between panel rows to allow for stormwater infiltration. Excess stormwater not absorbed by the vegetated strip would be directed into shallow bio-swales along each row. Stormwater flow not absorbed in these swales would be carried down the terraces via proposed conveyance ditches and directed to the existing culvert that also carries the flow of the intermittent stream to the east.


Figure 4: Drawing of Typical Section of Proposed Stormwater Management System

The report concludes that the proposed stormwater management strategy will not create flooding conditions or circumstances, and as currently designed the stormwater management system may actually improve stormwater drainage flows in the project vicinity. These improvements would come by diverting stormwater flows currently directed toward the Bernert Creek, which currently has limited stormwater capacity, to a new location further east and closer to the project site access road, where stormwater capacity is sufficient. No Significant Effect to Water Resources Since the project completely avoids impact to regulated wetlands and waterways, and adequate capacity exists to accommodate changes to stormwater flows, there are no significant effects to water resources. The project will not adversely affect water quality or increase the likelihood of flooding as a result of changes in stormwater runoff. This conclusion is supported by the low impact development techniques planned for the project as well as the diversion of existing stormwater flows to drainages with greater capacity to handle stormwater flows. Additional Resources To obtain a complete copy of the Wetland and Waters Delineation Report please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Wetland_Delineation_Rpt_Part_1.pdf To obtain a copy of ODOT correspondence with the U.S. Army Corps of Engineers please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/CorpsEngineers_Ltr.pdf To obtain a copy of ODOT correspondence with the Department of State Lands please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/StateLands_Ltr.pdf To obtain a complete copy of the Stormwater Drainage Report please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Stormwater_Rpt.pdf


Land Use All transportation projects must comply with state and local land use regulations. These regulations are designed to ensure that land is used efficiently for the benefit of the wider economy and population as well as to protect the environment. State Land Use Goals are implemented by local city and counties, through the adoption and acknowledgement of comprehensive plans by the State of Oregon Department of Land Conservation and Development. The City of West Linn has an acknowledged comprehensive land use plan and community development code. Existing Conditions The proposed project is located within the city limits of West Linn in Clackamas County, Oregon but is located entirely on state-owned property designated as highway right-of-way. The property is on a south-facing slope that features three terraced benches that rise above I-205. The benches were created in 1969 during the construction of the interstate to stabilize the slope and protect the highway from a landslide. A portion of the lowest bench is currently utilized by ODOT as a maintenance and storage yard and is accessible from southbound I-205 via a half paved and half unpaved driveway. While the remainder of the site has been left largely undisturbed since the construction of the interstate allowing some small stands of trees to grow, most of the site consists of dry grasslands dominated by non-native grasses and forbs. The site also features several small wetlands primarily in low-lying ditches along I-205. The site is bound to the east and west by the drainages of intermittent streams. To the north and above the upper bench the property adjoins a residential neighborhood, Barrington Heights. To the north and west, land uses are predominantly commercial and residential interspersed with some undeveloped open-space and agricultural uses. To the south and east, land uses are principally industrial with some residential and open-space uses. To the east of the property is a decommissioned highway rest area. South of the property across the interstate and Willamette Falls Drive is a school bus storage yard. The Willamette River is located approximately a quarter mile south of the project area and the Willamette Falls Dam and Locks are located approximately one-mile downstream.


Review of Applicable Land Use Regulations and Ordinances City of West Linn Comprehensive Plan and Community Development Code Upon ODOT's request, the City of West Linn reviewed its Comprehensive Plan, the community's overarching framework for land use decisions, and Community Development Code, the rules that implement the community's Comprehensive Plan, to identify the applicability of any local land use regulations to proposed project. The City of West Linn initially advised ODOT that the City's land use rules did not apply because the proposed project is an operational improvement for ODOT's use and would occur entirely within ODOT owned right-of-way. This conclusion is consistent with how other transportation improvements in highway right-of-way are treated by local jurisdictions in the Portland metropolitan area. The initial advice also found that other development standards do apply to the project, including the City's stormwater engineering standards and tree removal procedures. Upon further review and discussion with ODOT, the City of West Linn recommended that their initial advice be subject to an official "Planning Director Interpretation," as set forth in the Community Development Code. This process will provide opportunities for additional public participation. City of West Linn's Comprehensive Plan and Zoning Maps The City of West Linn's official Zoning and Comprehensive Plan maps show most of the project area as unzoned I-205 right-of-way. However a portion of the site appears on the official maps as having residential zoning. The dual zoning seems to arise from ODOT's acquisition of the northern portion of the site during the construction of I-205 in the late 1960s. At that time, ODOT acquired a number of additional parcels as highway right-of-way in order to terrace and stabilize the slope. However, tax maps produced by the Clackamas County Assessor’s Office did not properly map the additional acquisition as public right-of-way and showed, in error, the acquired parcels as individual freestanding tax lots. The City of West Linn relied on the erroneous mapping when it overlaid residential zoning to the northern portion of the site, mistaking the previously acquired and consolidated parcels as freestanding lots. When it became aware of the mapping error in 2009, ODOT requested that the Clackamas County Assessor's Office consolidate the freestanding tax lots into the I-205 right-of-way. The Assessor's Office approved the request and changed the tax map in April 2009 removing the freestanding tax lot lines. The City of West Linn then followed suit by removing the lots from the zoning map. However, the northern portion of the property is still officially zoned residential.


The City of West Linn and ODOT recognize the inconstancy in having a portion of ODOT owned right-of-way designated as a residential zone and are working together to resolve the matter by applying an appropriate process prescribed by the City of West Linn's Community Development Code. City of West Linn's Park and Open Space Plan The City of West Linn's Park and Open Space Plan proposes that a portion of the site be developed with a bicycle and pedestrian greenway trail and trailhead. According to city officials, the parks plan is a visioning document and is not a regulatory land use ordinance. Additionally, the parks plan acknowledges that any development of recreational facilities on the property would be subject to ODOT approval. The proposal for a bicycle and pedestrian greenway trail is not integral to the development of the proposed solar array. While ODOT is cooperating with the City of West Linn on the matter by ensuring that the solar project design would not prohibit a bicycle/pedestrian through connection, the trail would be separate and distinct from the current proposed project and subject to its own design, environmental, and funding processes. The trail project is not contingent upon the solar project, and vice versa. The project will comply with all applicable land use regulations. All required approvals will be obtained from the City of West Linn before a final commitment will be made to finance and construct the project. Additional Resources To obtain copies of ODOT's correspondence with the City of West Linn please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Zoning_Ltr_Apr09.jpg and http://www.oregon.gov/ODOT/COMM/docs/docs/Zoning_Ltr_Mar10.pdf Hazardous Materials The presence of hazardous materials and the problems associated with them can pose human health and environmental risks in addition to financial liability. Because of these risks, the generation and handling of hazardous materials are strictly regulated by both state and federal agencies. Prior to embarking on a transportation project, it is important to identify potential hazardous materials that might be encountered or generated during construction. ODOT begins this process by conducting a preliminary hazardous materials assessment to identify if any potentially hazardous materials are present within the project site and to characterize the nature of the materials present at the site. If concerns are identified in this initial evaluation, then ODOT conducts further research to


determine the extent of contamination and ascertain if the materials pose a human health or environmental risk. An ODOT Hazardous Materials specialist visited the site of the proposed project two times during the summer of 2009. During these visits the specialist looked for evidence of obvious contamination sources such as materials that might contain asbestos or lead-based paints. The site visits revealed the presence of small amounts of waste materials of concern including metal and concrete, abandoned automobile tires and an old appliance with exposed insulation. While these materials are not expected to contain any potentially hazardous materials, the specialist recommended they be removed and disposed of recycling the materials where possible. The maintenance and storage yard, which is outside of the footprint of the proposed solar array, contained concrete barriers, a small garage, several cubic yards of road sweepings, painted bridge components and a partially paved asphalt and gravel roadbed. It is possible that the road sweepings, bridge components and gravel in the roadbed contain small quantities of petroleum, metals or other contaminants. Additionally, the specialist reviewed reports from various environmental databases, interviewed the supervisor of the maintenance and storage yard and examined historic aerial photographs of the site in an effort to determine if evidence existed to point to potential sources of contamination. This review of secondary sources revealed no indication that the property had any unseen sources of contamination. No Significant Effect from Hazardous Materials Based on these findings, ODOT concluded that the proposed project would not encounter any sources of hazardous materials that could impact human health or the environment. Additional Resources To obtain a copy of the Hazardous Materials Assessment please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Hazmat_Rpt.pdf Noise Unwanted and excessive sound can be an undesirable by-product of transportation activities. Noise can create annoyances, interfere with daily life and in the extreme cause psychological or physical harm. In response to the problems associated with noise pollution, state and federal agencies have established regulations and standards limiting and mitigating noise from transportation projects, construction and maintenance activities.


The NEPA review process requires ODOT, acting on behalf of the Federal Highway Administration, to consider if a proposed project will create a clearly noticeable or significant increase in noise levels compared to current conditions. The Oregon Department of Environmental Quality has also established limits on the allowable amount of noise from stationary sources. Other Federal Highway Administration noise rules do not apply to the proposed West Linn site because the proposed project does not involve the construction of a new highway or the alteration of an existing one. Noise Analysis In order to assess the potential impact to noise levels resulting from the development of the proposed project, ODOT conducted a noise analysis. ODOT acoustic team identified nearby sensitive noise receptors (people in places they regularly live or work) that could potentially be affected by noise from the proposed project, measured existing noise levels at the project site and predicted how proposed changes, specifically the operation of solar power inverters and the effect of tree removal, would impact noise levels. Potential Noise Impacts of Solar Power Inverters The noise report concluded that the proposed project would not result in a noticeable increase in noise levels compared to current conditions. According to ODOT's acoustic team, using conservative assumptions, the proposed solar power inverters will increase noise levels at residences at the north edge of project site by a maximum of 3 decibels (dBA) a change in noise level that is barely perceptible to the human ear. Further, this change in noise level would only occur at the beginning and end of the daylight hours in spring and summer, when traffic volumes are assumed to be lower. At all other times the noise levels at the closest residences would increase by 2 dBA or less a change in noise level imperceptible to the human ear. At night when the solar inverters are not operational there will be no change in noise levels compared to existing conditions. The acoustic team also concluded that the topography and terrain of the project site provides a noise shielding benefit to residences along the north edge of project site from traffic noise and that these same features may further shield these residences from any potential inverter noise. Tree Removal Potential Noise Impacts The noise report also considered the consequences of tree removal associated with site preparation activities. Vegetation can only attenuate and provide clearly noticeable reduction of noise levels if it is tall enough, wide enough and dense enough that it cannot be seen through. To accommodate the solar arrays and maximize the potential for electricity generation, the proposed project may require the removal of as many as 268 trees from the lower and upper benches. ODOT's acoustic team concluded that the density of these trees


located in the line of sight between residences and freeway is not sufficient to significantly reduce traffic noise and that their removal will not result in a clearly noticeable or significant increase in noise levels compared to existing conditions. No Clearly Noticeable Increase in Noise Levels Based on the findings of the noise analysis, the proposed project will result in no clearly noticeable or significant changes to noise levels. Additional Resources To obtain a copy of the Noise Analysis please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Noise_Rpt_Final.pdf


Visual and Aesthetic Resources The NEPA review process requires ODOT, acting on behalf of the Federal Highway Administration, to consider a proposed project’s effect to visual and aesthetic resources. Visual resources are those physical and aesthetic elements that constitute the visible landscape or viewshed such as landforms, bodies of water, vegetation and human-made structures. Visual resources with natural scenic qualities have important community and economic value. Visual resources can help define a community's identity, character and sense of place. They can also add to quality of life and support local economies by sustaining property values and attracting visitors. The purpose of considering the potential impact to these visual resources is to ensure that a proposed project does not degrade theses values. Visual Resource Report In order to assess if the proposed solar array would result in significant adverse visual impacts, ODOT commissioned a licensed landscape architect to provide a professional evaluation of the existing landscape aesthetics and the consequences of the proposed project to those aesthetics. The analysis underpinning the report includes field visits to the proposed project site and to viewpoints in West Linn and Oregon City and a review of before and after project renderings. Existing conditions The report characterizes the existing conditions of the site and its immediate surroundings as highly modified from its natural condition and calls out the ODOT maintenance and storage yard, adjacent housing developments, nearby industrial land uses and the decommissioned highway rest area. This, the report states, results in a reduction in the visual quality compared with underlying natural conditions. However, the report notes that despite the fact that the existing visual resources are not pristine they still retain some aesthetic value. The report considered the effects to the existing scenic conditions from two perspectives––from along the upper bench to the north of the proposed project site (the property boundary adjacent to the Barrington Heights neighborhood) and from along Canemah Bluff (approximately 1 mile south across the Willamette River in Oregon City). Potential Effects to the Barrington Heights Viewshed The report concluded that most, if not all, of the project will not be visible from homes in the Barrington Heights neighborhood. This conclusion was determined by plotting lines of site from the closest homes to points along the lower benches. While the line of site indicates a viewer from the top of the hill to the northeast may be able to see a portion of the lower bench, it is likely that existing vegetation along the upper bench would


either partially or completely obstruct the line of site. Vegetation along the upper bench will not be removed as part of the project development1. Potential Effects to the Canemah Bluff Viewshed The report concludes that the proposed project site is more visible from Canemah Bluff and that the proposed project will, to an extent, accentuate the unnatural linear features of the terraced benches. However, the report notes that the scale of the project area is small relative to the wide panoramic view from the Bluff and as a result, the impact to the existing scenic conditions will be minimal. Additionally existing vegetation in the Canemah Bluff natural area will eventually reach a height that will at least partially obscure the existing view from the Bluff. The images below show the existing view from Canemah Bluff (Figure 5) and a rendering of the view with the proposed project in place (Figure 6). Figure 5: Summer view of project site from Canemah Bluff without proposed installation

1 While vegetation will not be removed from the upper bench as part of the proposed project, since this portion of the right-of-way is outside the project footprint, ODOT and the adjoining property owners may potentially enter into a maintenance or stewardship agreement that would allow planting and maintenance of a buffer strip between their property lines and the solar array and to allow landscape restorationactivities.


Figure 6: Summer view of project site from Canemah Bluff with proposed installation

No Significant Effect to Visual Resources Based on the findings of the Visual Resources Report, the likely impacts to local scenic conditions are small and will not result in a significant effect to visual resources. Additional Resources To obtain a copy of the Visual Resources Report please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Visual_Rpt.pdf Socioeconomic The construction and maintenance of transportation projects can disrupt local communities and economies through the displacement and dislocation of people, businesses and public services. These disruptions can have adverse effects on community cohesion and economic vitality. The NEPA process requires ODOT, acting on behalf of the FHWA, to consider a proposed project’s potential to negatively affect employment, property values and access to community services. Furthermore, state and federal environmental justice guidelines direct ODOT to avoid, minimize or mitigate


adverse social and environmental impacts that are disproportionally borne by minority and low-income populations. Community Cohesion and Economic Vitality The proposed project will not result in the temporary or permanent displacement of any residences, businesses or community services and therefore, is unlikely to have any significant impact on community cohesion or economic vitality. Furthermore, the proposed project will not fundamentally alter the site's existing use as a location for auxiliary services that support transportation infrastructure. Some members of the public have expressed concern that the proposed project may negatively impact their property values. No known studies support the contention that proximity to solar arrays impacts property values. An analogous study conducted by the U.S. Department of Energy Lawrence Berkeley National Laboratory examining the impact of wind power projects on residential property values found no widespread negative property value impacts2. Rather than causing adverse impacts to economic vitality, the project has the potential to boost local and statewide economic activity acting as a draw for tourism. Also, most of the material components will be manufactured or assembled in Oregon, providing a boost to those industries in the state. Environmental Justice No environmental justice issues have been identified associated with the proposed project. Potential environmental justice impacts were determined by analyzing the demographic composition of populations in the immediate vicinity of the project and considering the likelihood that project impacts would disproportionately effect low-income or minority populations. An analysis of census block-level demographic data from the 2000 U.S. Census identified the presence of minority and low-income populations in several census blocks close to the project. Foreseeable impacts to low-income and minority populations include temporary construction impacts and the slight diminution of scenic conditions. There is no indication that these effects would be disproportionately borne by low-income and minority populations. Furthermore, no environmental justice concerns have been raised either during the public involvement process or directly to ODOT.

2 Hoen, B., R. Wiser, P. Cappers, M. Thayer, and G. Sethi (2009). The Impact of Wind Power Projects on Residential Property Values in the United States: A Multi-Site Hedonic Analysis. LBNL-2829E. U.S. Department of Energy Lawrence Berkeley National Laboratory. Berkeley, CA.


Geotechnical Geotechnical engineering is a specialized branch of civil engineering that makes sure transportation infrastructure projects will be structurally sound in relation to the surrounding geologic conditions. These engineers make sure that the construction and operation of transportation infrastructure will not create geologic hazards such as slope instability (landslides, rockfall) and soil failures (sink holes, erosion). Issues of geologic stability are particularly relevant for the proposed project given the history of landslides at the project site. Geotechnical Report ODOT commissioned a licensed geotechnical engineering firm to perform a slope stability analysis and geotechnical evaluation in order to determine the present condition of the project site and evaluate the potential for the proposed project to undermine slope stability. The engineering firm walked the entire site in the field, reviewed historic aerial photographs and geotechnical reports, considered current remote sensing images and data, conducted soil and rock core sampling, performed laboratory testing of rock and soil samples and utilized sophisticated computer models to determine the stability of the existing slope and prepare the report. Existing Conditions Based on this analysis, the geotechnical engineering firm concluded that there were no slope stability issues and there is no likelihood of landslides similar to the ones that previously occurred on the site because the previous grading and terracing activity removed the unstable rocks and soils that caused the slides. Furthermore, the report concluded that there are no slope stability conditions that present a hazard to adjacent properties. Potential Impacts from the Proposed Project The geotechnical engineering firm also concluded that site preparation and construction activities would have no impact on slope stability. These activities include tree removal, the conceptual design for the proposed project and solar panels mounted on concrete block foundations. The firm did have specific technical recommendations for the design and construction of the proposed developments. These recommendations included: the implementation of construction best management practices, control of stormwater runoff, erosion control measures, avoidance of wet weather construction and the use of appropriate fill material in ground leveling.


During final design, registered engineers will ensure that the recommendations made by the geotechnical firm are incorporated, to ensure stability during construction and afterward. No Significant Effect to Slope Stability Based on the report the proposed project is not expected to present any risk to slope stability. Additional Resources To obtain a copy of the Slope Stability Analysis please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Slope_Stability_Rpt.pdf Air Resources Air pollution can cause serious human health effects and be detrimental to natural resources. Transportation infrastructure projects and programs can adversely affect air quality both by changes in the volume and timing of vehicular traffic and construction and demolition activities. A host of state and federal regulations, including the Clean Air Act, ensure that ODOT analyzes and considers the potential impact to air quality resulting from proposed project activities and decisions. Potential Impacts to Air Quality Because the proposed project would not add capacity to transportation facilities nor increase vehicle miles traveled, day-to-day operation of the solar array would have negligible impacts to air quality in the Portland metropolitan area. Over the long term, because the proposed project would reduce ODOT’s reliance on energy derived from fossil fuels, it is expected that regional and/or statewide air quality would be actually benefit from the solar array project. During construction, there could be short-term air quality effects due to operation of heavy construction vehicles and earth excavation. These activities could create temporary impacts on ambient air quality. No burning of construction wastes will be allowed. Construction effects to air quality would be mitigated through implementation of air pollution control measures such as limitations on heavy truck and construction equipment idling and dust suppression, as specified in ODOT's standard construction contract specifications. No Significant Effect to Air Resources The proposed project will have no meaningful impacts on traffic volume or vehicle mix and is therefore unlikely to impact air quality. Indeed, the project will have the indirect


effect of reducing regional air pollution by displacing fossil fuel derived electricity generation. Archaeological and Historic Resources The NEPA review process considers more than just the potential impact to natural resources it also considers the potential effect to archeological and historic resources. Archeological resources are locations of prehistoric and historic human activity that contain artifacts or distinct features. Historic resources are human built structures or properties with a significant connection to historic events. It is recognized that protecting these resources plays an important role in preserving collective cultural heritage and is critical in understanding the past. Several federal and state laws govern the protection and management of archeological and historic resources including the National Historic Preservation Act, the Department of Transportation Act (Section 4(f)) and the Archaeological Resources Protection Act. These statutes detail the specific regulatory requirements, which ODOT, acting on behalf of FHWA, must satisfy. No Significant Effect to Archaeological Resources The responsibility for ensuring that significant archaeological resources are considered for a proposed project rests with ODOT's Geo-Environmental Services Section archaeological staff. Given that many of Oregon's archeological resources may also possess a cultural significance to one of Oregon's federally recognized Native American Tribes, agency staff frequently coordinates with Tribal organizations. The extensive excavation and terracing of the project area left the site in a highly modified and disturbed condition and as a result, no impacts to archaeological resources are expected. After a review of existing records and coordinating with the Confederated Tribes of Siletz and the Confederated Tribes of the Grand Ronde Community of Oregon, an ODOT archaeologist concluded that the proposed project is unlikely to have significant impacts to archaeological resources. No Significant Effect to Historic Resources It is the responsibility of ODOT's cultural resource specialists to identify and evaluate historic resources potentially affected by a proposed project. After a review of existing records, an ODOT historian concluded that the proposed project is unlikely to have significant impacts to historic resources. This conclusion is supported by the fact that no historically significant properties are located near or within the proposed project site. Additional Resources


To obtain a copy of the correspondence from ODOT's historian or archaeologist please visit: http://www.oregon.gov/ODOT/COMM/docs/docs/Archaeology_Rpt.pdf and http://www.oregon.gov/ODOT/COMM/docs/docs/Historic_Rpt.pdf Environmental Commitments ODOT is committed to the protection and preservation of our state's unique natural and human environment and makes every effort to pursue solutions that meet the project need while protecting, restoring, and enhancing the environment. To meet this commitment ODOT has developed Standard Specifications for Construction that describes a contractor's duties and obligations with respect to protection of the land, waters, air, wildlife, and other environmental resources. The will require to the project developer to meet the requirements of these specifications. Additionally, ODOT has agreed to implement a number of project-specific environmental and sustainability best practices. Wildlife Species and Habitat Commitments ODOT will require the project developer to: • Avoid the disturbance of migratory birds by limiting the timing of tree removal and

ground disturbing activities to periods outside of the spring nesting season (April 30 through June 1);

• Coordinate the removal of trees with the Oregon Department of Fish and Wildlife to salvage and save large trees so they may be used in regional riparian restoration projects;

• Make arrangements to replace felled trees on a two-to-one basis in suitable regional ecological restoration projects;

• Where feasible make use of native plants in revegetation and landscaping Water and Wetlands Commitments ODOT will require the project developer to: • Implement pollution control measures to protect water quality including treatment of

contaminated or sediment-laden waters and containment measures to prevent pollutants or construction and demolition materials from entering surface waters

• Construct appropriate low-impact development stormwater facilities including vegetated infiltration strips and bioswales to treat stormwater runoff; and,

• Avoid all impact within a 50 foot buffer from the top of the stream bank at the west side of the site.


Air Quality Commitments ODOT will require the project developer to: • Use ultra-low sulfur diesel or a 20% blend of biodiesel with ultra-low sulfur diesel for

trucks and equipment in order to minimize emissions and maintain air quality while safeguarding the health of construction workers and local residents.

Geotechnical Commitments ODOT will require the project developer to follow the specific technical recommendations from the Slope Stability Evaluation including: • Inspection and supervision of construction activities by a qualified geotechnical

engineer; • Avoidance of wet weather construction; and, • The use of appropriate fill material in ground leveling. Additional Resources To obtain a copy of the ODOT's Standard Specifications for Construction please visit: http://www.oregon.gov/ODOT/HWY/SPECS/standard_specifications.shtml - 2008_Standard_Specifications

Documents

Summary of Proposed West Linn Solar Highway Project Site