Loading...
01.17.2007 - GeoEngineers 4 s GEOENGINEER� January 17, 2007 City of Tigard. 13125 SW Hall Blvd. Tigard,Oregon 97223 Attention: Mr. Dennis Koellermeier Subject: Proposal for Environmental Services Tigard Library 13500 SW Hall Boulevard Tigard, Oregon File No. 4025-003-02 INTRODUCTION AND OBJECTIVES This letter presents our proposed scope of services, schedule, and estimated budget for conducting environmental services related to arsenic-related soil contamination at the Tigard Library property, located at 13500 SW Hall Boulevard, Tigard, Oregon (hereafter referred to as "site"). The objectives of the proposed services are to: 1) establish site-specific cleanup levels that are protective of human and ecological health; 2) develop a remedial action plan for addressing contaminated soil at the site; 3) develop a soil management plan that will be useful during planned construction in the Wall Street right-of-way and 4)documenting the remedial actions in a remedial action report that will be submitted to the Oregon Department of Environmental Quality (DEQ). The goal of the proposed services is to complete site remediation and obtain a no further action determination from DEQ. The general scope of services presented in this proposal was discussed during a December 22, 2006 meeting between GeoEngineers Inc. and Mr. Dennis Koellermeier and a January 10, 2007 telephone conversation between GeoEngineers and Mr. Loren Gardner,the DEQ site manager. BACKGROUND Environmental assessment and remediation activities have occurred at the site since 2002. Assessment activities were conducted by Apex Environmental Consulting Services, Inc. (APEX) and Hahn and Associates, Inc. (Hahn) and included soil sampling at numerous locations at the property. In July 2003, prior to construction of the library, Apex observed the excavation of approximately 3,600 tons of arsenic-contaminated soil from within the footprint of the library and associated parking areas. In November 2005 Hahn observed the excavation and off-site disposal of approximately 155 tons of soil from within the proposed footprint of a bicycle path. Hahn conducted additional assessment activities in May 2006 to refine the understanding of the magnitude and extent of contamination at the site. Data presented by Hahn indicate that arsenic remains in soil in five areas of the site at concentrations exceeding generic human and ecological risk screening levels: 1)the "Southern Area" a Swale that runs west-east near the south boundary of the property; 2) the "Northern Area", a southwest-northeast trending swale at the north side of the site; E8►thS,ClenG94i8Cdaotogyt5055.SW Sequoia Pkwy telephone 503.624,9274 Suite'140 facsimile 503.620.$440 97224 website www.geoenginears.com City of Tigard January 17, 2007 Page 2 3) the "Pine Tree Area", a pine tree near the main entrance to the library; 4) the "Central Tree Area", a landscaped area in the middle of the library parking lot; and 5) the "Southwest Margin" a narrow area at the margin of the Apex 2003 remedial excavation area. Hahn recommended completion of a human health risk assessment (HHRA) to calculate cleanup levels that are protective under current and reasonably likely site conditions. Hahn also recommended completion of Phase I and Phase II ERA's based on the results of a Level I Ecological Risk Assessment (ERA)site reconnaissance(by GeoEngineers). DEQ indicated that a human health risk assessment and Level I and II ERAS should be conducted at the site during a January 10, 2007 telephone conversation. DEQ also indicated that additional assessment was necessary south of the site; however, DEQ indicated that the off-site assessment was likely not the responsibility of the City of Tigard, assuming that the arsenic originated at off-site location(s). Finally, DEQ indicated that some remediation of contaminated soil was likely necessary and that the cleanup levels would be determined based on the risk assessments. PROPOSED SERVICES GeoEngineers proposed services include: • Development of a conceptual site model and data evaluation. • Completion of a human health risk assessment. • Completion of Level I and II ERAS. • Development of a remedial action plan. • Development of a soil management plan. • Completion of a remedial action report. Each of these proposed tasks is described below. GeoEngineers proposed services do not include additional off-site assessment; however, we can easily add those services if requested by the City of Tigard. CONCEPTUAL MODEL AND DATA EVALUATION GeoEngineers will prepare a conceptual site model (CSM). The objective of the conceptual site model is to identify potentially complete contaminant transport and exposure pathways and receptors at the site. GeoEngineers will also evaluate the quality of the data collected to date by Apex and Hahn. The purpose of completing the data evaluation and CSM is to develop information that will serve as a basis for both the HHRA and ERAS. We assume that data tables prepared by Hahn will be available to GeoEngineers in electronic format. HUMAN HEALTH RISK ASSESSMENT GeoEngineers will complete an HHRA. The purpose of the HHRA is to calculate site-specific cleanup levels that are appropriate for protection of human health. The HHRA will include evaluation of the following exposure scenarios: 1) occupational (i.e. librarian); 2) short term user(s) (i.e. maintenance worker and park user)and 3)construction workers. File No.4025-003-02 GEOENGINEERir/P City of Tigard January 17, 2007 Page 3 We assume that this task will include as many as two meetings with City of Tigard personnel and one meeting with DEQ. We also assume that electronic versions of site maps and sampling figures will be provided to GeoEngineers by Hahn. We will submit a draft copy of the HHRA for review by the City of Tigard and DEQ. Following receipt of comments, if any,we will submit a final copy of the HHRA. LEVEL I AND II ECOLOGICAL RISK ASSESSMENTS GeoEngineers will complete Level I and Level II ERAs. The purpose of the Level I ERA is to assess whether ecologically valuable habitat may be present at the site. The purpose of the Level II ERA is to identify the ecological receptors that occur or are expected to occur at the site and to determine appropriate cleanup levels for those receptors. The Level I and II ERAS will be conducted for terrestrial receptors only. GeoEngineers has already completed the Level I ERA site reconnaissance. The results of the Level I and Level II ERAs will be presented together in a single report. We will submit a draft copy of the Level I and II ERA for review by the City of Tigard and DEQ. Following receipt of comments, if any,we will submit a final copy of the Level I and II ERA. REMEDIAL ACTION PLAN GeoEngineers will prepare a remedial action plan (RAP) following completion of the HHRA and ERAs. The RAP will present GeoEngineers' recommended approach for remediating contamination at the site. Based on our discussions with the City of Tigard and DEQ, we anticipate that the RAP will include one or more of the following remedies: 1) engineering controls, such as capping of contamination (with soil and/or asphalt) and/or fencing, etc. to restrict access; 2) excavation with off-site disposal and 3) institutional controls, such as restrictions on future development in impacted areas of the site. The selection of the appropriate remedies will be based on: 1) input from the City of Tigard and 2) the cleanup levels established during the HHRA and ERAS. We assume that completion of the RAP will require as many as two meetings with the City of Tigard and one meeting with DEQ. We will submit a draft copy of the RAP for review by the City of Tigard and DEQ. Following receipt of comments, if any, we will submit a final copy of the RAP. SOIL MANAGEMENT PLAN GeoEngineers will prepare a soil management plan (SMP). The SMP will provide guidelines for handling arsenic-contaminated soil at the site. The SMP is intended for use by City of Tigard personnel and City of Tigard contractors. The SMP will include recommendations for: 1) excavation, stockpiling, placement, and disposal of contaminated soil; 2) sampling and analysis requirements and 3)worker health and safety. We will submit a draft copy of the SMP for review by the City of Tigard. Following receipt of comments, if any,we will submit a final copy of the SMP. REMEDIATION REPORT GeoEngineers will prepare a remediation report. The purpose of the remediation report is to document the remedial activities at the site. The goal of the remedial action report will be to demonstrate that residual contamination at the site does not pose an unacceptable risk to human or ecological health. The remediation report will include: 1) a summary of the remedial activities completed at the site; 2) a comparison of residual arsenic concentrations in soil to cleanup criteria and 3) a summary of institutional and/or engineering controls applied to the site, if any. We will submit a draft copy of the remedial action report for review by the City of Tigard and DEQ. Following receipt of comments, if any, we will submit a final copy of the remedial action report. File No.4025-003-02 GWENGINEER� City of Tigard January 17, 2007 Page 4 PROJECT SCHEDULE We understand that the City of Tigard plans to begin the road improvement project in the Wall Street right-of-way in approximately July 2007. We anticipate that we can complete the HHRA and ERAs and develop the remedial action plan prior to the scheduled road improvement activities, allowing the City to integrate remediation into the road construction, if feasible. The proposed schedule is presented below. Task Date Estimated Completion Develop Conceptual Site Model February 2,2007 2 weeks after authorization to proceed and Data Evaluation Submit Draft Human Health Risk February 16,2007 4 weeks after authorization to proceed Assessment Submit Final Human Health Risk March 16,2007 2 weeks after receiving comments(assume 2 Assessment weeks for DEQ comments) Submit Draft Level I and II February 16,2007 4 weeks after authorization to proceed Ecological Risk Assessment Submit Final Level I and II March 16,2007 2 weeks after receiving comments(assume 2 Ecological Risk Assessment weeks for DEQ comments) Submit Draft Remedial Action Plan April 6,2007 3 weeks after submission of the final drafts of the Human Health Risk Assessment and the Level I and If Ecological Risk Assessment Submit Final Remedial Action Plan May 4,2007 2 weeks after receiving comments(assume 2 weeks for DEQ comments) Develop Soil Management Plan April 20, 2007 2 weeks after submission of the final drafts of the Human Health Risk Assessment and the Level I and II Ecological Risk Assessment To be determined 6 weeks after completion of the remedial Submit Remedial Action Repo� activities PROJECT BUDGET We propose that the professional services listed above be provided in accordance with the Services Agreement, File No. 0615-ST06-13 (Agreement) between GeoEngineers and the City of Tigard. The fees for the services described above will be determined on a time-and-expense basis using the rates indicated on the Exhibit 2 of the Agreement. The estimated fees for the services outlined above are summarized below: Task Estimated Total Fee Develop Conceptual Site Model and Data Evaluation $3,400 Human Health Risk Assessment $13,000 Level I and II Ecological Risk Assessment $11,000 Remedial Action Plan $4,500 Soil Management Plan $1,500 Remedial Action Report $6,000 Total $39,400 File No.4025-003-02 GEOENGINEERurdl City of Tigard January 17, 2007 Page 5 We will keep you informed of project status and advise you if it appears appropriate to modify the scope and budget. AUTHORIZATION This proposal can be authorized by issuing a work order agreement under the terms and conditions of the services agreement between the City of Tigard and GeoEngineers dated December 22,2006. We appreciate the opportunity to present this proposal to provide services to you on this project. Please contact us if you have any questions concerning this proposal. Sincerely, GeoEngineers, Inc. Chris Breemer,R.G. Senior Project Manager John H. Biggane, Principal CWB:JHB:glb Document ID: P:\4\4025003\02\Finals\402500302P.doc Proprietary Notice: The contents of this document are proprietary to GeoEngineers,Inc.and are intended solely for use by our clients and their design teams to evaluate GeoEngineers'capabilities and understanding of project requirements as they relate to performing the services proposed for a specific project. Copies of this document or its contents may not be disclosed to any other parties without the written consent of GeoEngineers. Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record. Copyright©2007 by GeoEngineers,Inc. All rights reserved. File No.4025-003-02 GWENGINEERir/P