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HomeMy WebLinkAboutAgenda Report - July 21, 2010 D-05AGENDA ITEM DOWSP l pp; joCITY OF LODI Gam- 9</PORECOUNCIL COMMUNICATION AGENDA TITLE: Adopt Resolution Approving Task Orders No. 21 and 22 with Treadwell and Rollo, of Oakland, for Southern, South Central NVestern, and Northern PCE/TCE Plumes Workplan Preparation and Monitoring ($446,400) and Appropriating Funds ($500,000) MEETING DATE: July 21,2010 PREPARED BY: Public Works Director RECOMMENDED ACTION: Adopt a resolution approving Task Orders No. 21 and 22 with Treadwell and Rollo, of Oakland, for Southern, South Central/Western, and NorthernPCE/TCE Plumesworkplan preparation and monitoring in the amount of $446,400 and appropriating funds in the amount of $500,000. BACKGROUND INFORMATION: Staff and our consultants are moving forward on the implementation of Central Plume Interim Remedial Measures, including the construction of two groundwater extraction and nine soil vapor extraction wells and treatment facilities. It is now time to move forward on remediation actions for the Southern, South CentralNVestern and Northern plumes, the remaining unresolved contamination areas, under the authority of the Central Valley Regional Water Quality Control Board (RWQCB). Proposed Task Orders No. 21 and 22, attached as ExhibitA, provide for the preparation of two workplans (Southern/South Central/Western and Northern Plumes) for review/approval by the RWQCB, construction of monitoring wells, monitoring and reporting to the RWQCB for up to one year. During the one-year monitoring period, the workplans will be validated and modified as required. Following the validation period, the monitoring and reporting work will be combined with the Central Plume monitoring and reporting work and will be formally bid out. The goal of the Southern and South CentralNVestern plume monitoring is to demonstrate the relative stability of the plumes and to establish that active groundwater remediation will not be needed to mitigate groundwater contamination associated with the plumes. Monitored natural attenuation would be accepted by the RWQCB as the remedy if groundwater monitoring validates that the plumes are stable and/or shrinking. The Northern Plume has not been as extensively studied. The nature of this plume needs to be more extensively defined with respect to its lateral extent, general chemistry and contaminant/depth relationships. Per the Northern Plume Settlement Agreements, the City is responsible for remediation of the groundwater. Interim City Manager K:\WP\PROJECTS\WATER\PCE.TCE\CTRTaskNos 21.doc 7/13/2010 Adopt Resolution Approving Task Orders No. 21 and 22 with Treadwell and Rollo, of Oakland, for Southern, South CentralM/estern, and Northern PCEPTCE Plumes Workplan Preparation and Monitoring ($446,400) and Appropriating Funds ($500,000) July 21, 2010 Page 2 Substantial uncertainty remains but should these remedies be accepted by the RWQCB and prove to be successful, the City could realize cost savings roughly estimated to be in the range of $20 million - $25 million. FISCAL IMPACT: Operation and maintenance costs will increase and are funded by PCE/TCE Cleanupfunds. FUNDING AVAILABLE: Requested Appropriation: PCEPTCE Rates (185) — $500,000 Jordan Ayers Deputy City Manager/Internal Services Director F. Wally S delin PublicWorks Director FWS/pmf Attachment K:\WP\PROJECTS\WATER\PCE,TCE\CTRTaskNos 21.doc 711312010 Exhibit A . 1 ♦ 1 1 2 July 2010 P09-064 Mr. F Wally Sandelin City Hall Public Works Department 221 West Pine Street Lodi, California 95240 Subject: Scope, Schedule and Estimated Cost —Tasks 21 and 22 Preparing and Initiating Groundwater Monitoring Programs for the Southern and South Central/Western Plumes and Initial Strategy to Address the Northern Plume Lodi, California Dear Mr Sandelin: Treadwell & Rollo, Inc. (Treadwell & Rollo) is pleased to submit this proposal for Tasks 21 and 22 for services related to the groundwater remediation program in Lodi, California. The tasks include: 1)developing and initiating a groundwater monitoring program to address the Southern Plume and the South Central/Western Plume; and 2) developing a strategy to address contamination in the Northern Plume. SOUTHERN AND SOUTH CENTRAL/WESTERN PLUMES I n recent discussions with representatives of the Central Valley Regional Water Quality Control Board (RWQCB), agreement was reached to prepare a groundwater monitoring program for the Southern and South Central/Western Plumes, with the goal of demonstrating the relative stability of the plumes and to establish that active groundwater remediation will not be needed to mitigate groundwater contamination associated with the plumes. Monitored natural attenuation would be accepted by the RWQCBas the remedy if groundwater monitoring validates that the plumes are stable and/or shrinking. The attached Figure 1 shows the locations of existing wells and approximate isoconcentration contours for the principal chlorinated volatile organic compounds (VOCs) in the Southern and South Central/Western Plume areas. The Southern Plume area is located in the vicinity of the intersection of Kettleman Lane (Rt 12) and the Union Pacific Railroad tracks, extending from approximately Park Street on the north to just south of Kettleman Lane on the south, and School Street on the west to Stockton Street on the east. Chlorinated volatile organic compounds (VOCs) have been detected at depths up to 90 feet below the ground surface (bgs) in the 14 groundwater monitoring wells in the vicinity of the plume. I n 2008, the last year groundwater samples were collected, the major VOCs detected in the plume were PCE, at concentrations up to 740 micrograms per liter (lag/L), TCF, at concentrations up to 120 pg/L and 1,1-dichloroethene (1,1-DCE), at concentrations up to 150 pg/L. The eastern edge of the plume has not been fully defined and the deepest occurrence of VOCs in the plume has not been determined. The South Central/Western Plume area is located to the northwest of the Southern Plume and west of the off-site portion of the Central Plume. The plume, which may be composed of two smaller plumes with close source areas along and just south of Lodi Avenue, extends from Lodi Avenue on the north to York Street on the south and from approximately Orange Avenue on the west to Lee Avenue on the east. I n 2005 and 2006, VOCs were detected at depths up to 164 feet below the ground surface (bgs) in an investigation comprised of collecting grab groundwater samples from multiple depths in 23 borings. ENVIRONMENTAL AND GEOTECHNICAL CONSULTAN (S 501 14TH STREET. 3RD FLOOR OAKLAND CALIFORNIA 94612 T 510 874 4500 F 510 874 4507 www treadwellrollo com Mr. F Wally Sandelin City Hall Public Works Department 2 July 2010 Page 2 With the exception of shallow well MW -11 located on the western edge of the plume, there are no existing groundwater monitoring wells in the area of the South Central/Western Plume. The major \ADC detected in the plume was PCE, at concentrations up to 550 pg/L in a sample on Sturia Street. The southern boundary of the plume has not been well defined and the deepest occurrence of VOCs has not been determined. The South Central/Western Plume's close proximity to the western edge of the Central Plume has implications in the possible design of remediation approaches for the Central Plume as the potential exists that active groundwater removal in the Central Plume could cause groundwater in the South Central/Western Plume to be pulled into the Central Plume, potentially spreading groundwater contamination from the west to the east in areas currently not contaminated. The purpose of the monitoring program for the two areas will be to complete the definition of the impacted areas and to monitor the stability of the plumes by regular monitoring, as part of the current city-wide monitoring program. Data collected by the monitoring program will be used to evaluate changes in the extent of the plumes and to determine the adequacy of monitored natural attenuation as the appropriate remedial approach. Tasks described below include performing a preliminary groundwater investigation to evaluate the contaminant chemistry with respectto aquifer depth in the Southern Plume, preparing a groundwater monitoring program plan for City and RWQCB approval, design and installation of monitoring wells, and performing initial rounds of groundwater monitoring for one year on a quarterly or semi-annual basis, as specified in the approved groundwater monitoring plan. NORTHERN PLUME The Northern Plume groundwater contamination has not been as extensively studied as the Southern and South Central/Western Plumes. The Northern Plume area is located north of the Lodi Central Plume area and is approximately bound to the north by Turner Road, to the east by Washington Street, to the south by Elm Street and to the west by Church Street. Soil vapor and groundwater investigations have previously been performed in the Northern Plume area by URS Consultants, Henshaw Associates, Geomatrix and others. Chlorinated VOCs have been found in groundwater in the Northern Plume at up to 400 feet bgs. The most prevalent chlorinated VOC was TCE, which has been reported at concentrations up to 210 tag/L. PCE was reported in one sample at 74,000 pg/L, although in all others analyses examined, the highest PCE concentration was 110 pg/L. Other chlorinated VOCs have been reported at lower concentrations and non -chlorinated aromatic VOCs (such as toluene and xylenes) have also been reported at low concentrations. The nature of this plume needs to be more specifically defined with respectto its lateral extent, general chemistry and contaminant/depth relationships. Our recommended approach for addressing this plume is described in Task 22, SCOPE OF WORK TASK 21 GROUNDWATER MONITORING PROGRAM, SOUTHERN AND SOUTH CENTRAL/ WESTERN PLUMES Task 21a Southern Plume Data Collection The current data for the Southern Plume was collected in April of 2008. To assist us in developing the monitoring program, we propose to collect current and depth specific groundwater chemical data by advancing soil borings for grab groundwater samples and collecting a round of samples from the existing • Mr. F. Wally Sandelin City Hall Public Works Department 2 July 2010 Page 3 wells in the plume area. Prior to sampling, we will prepare a brief technical memorandum explaining our sampling rationale for presentation during a meeting with the RWQCB to obtain their approval. All previous available groundwater samples used to define this plume were collected at depths less than 90 feet bgs, generally from wells screened from 50 to 90 feet, 55 to 80 feet, or 55 to 75 feet. The highest reported PCE concentration was in well OS -02, screened from 50 to 90 feet. To properly monitor this plume, better definition of the depths of contaminants must be developed. We propose to collect stratigraphic and depth -discrete chemical information by advancing test borings or cone penetration test (CPT) probes in three to four locations, to be determined during initiation of the project. We plan to collect grab groundwater samples by Geoprobe samplers at up to 6 depth intervals to a maximum of 200 feet bgs. The data collected will be used to evaluate monitoring well locations and specifications for the monitoring program. I n addition, we proposeto sample all fourteen wells currently present, which were last sampled in 2008, to determine if changes in concentrations of VOCs have occurred over the last 27 months that could impact our assessment of additional monitoring well locations and designs. Task 21 b Prepare Groundwater Monitoring Program Plan Treadwell & Rollo will prepare a Groundwater Monitoring Program Plan (Plan) for the two plume areas. The Plan will summarize existing knowledge of the plumes, identify data quality objectives and cleanup goals, present the plan of specific wells to monitor, and propose a schedule of initial sampling events. The Plan will also propose additional wells to be installed, including rationale, location, and screened intervals. Appended to the plan will be a Quality Assurance Program Plan (QAPP) and a Sampling and Analysis Plan (SAP). An initial draft plan will be prepared and submitted to the City for one round of review and comment. After revision to address City comments, the draft plan will be presented to the RWQCB in a meeting and submitted for review and comment, and subsequently revised and finalized for RWQCB approval. As initial groundwater monitoring proceeds (Task 21e), the monitoring program will be reevaluated and revised, if warranted by the data collected. A final Groundwater Monitoring Program Plan will be prepared for presentation to and approval by the RWQCB. After obtaining approval, the plan will be incorporated into the Cityis Groundwater Monitoring and Reporting Program. Task 21c Design Additional Monitoring Wells Treadwell & Rollo will prepare monitoring well designs and well -installation contracting packages for the proposed additional wells recommended and approved in the Plan. For this proposal, we have assumed the installation of the wells listed below. We expect the number and construction parameters for these wells will be changed during development of the monitoring program. • Southern Plume Area Three well nests of two-inch diameter wells, each constructed to monitor specific depth intervals. Each well nest is assumed to include 3 to 4 discrete sampling depth intervals, which will be specified in the monitoring plan, based on the preliminary groundwater sampling (Task 21A). 1 ♦ 1 1 Mr. F. Wally Sandelin City Hall Public Works Department 2 July 2010 Page 4 South Central/Western Plume Area Four well nests of two-inch diameter wells, each constructed to monitor specific depth intervals. Each well nest will contain 2 to 4 wells, as determined by the chemical depth intervals evaluated in our 2006 study. Preliminary well nest locations are as listed below and shown on Figure 1. 1)on Sturla Street between Hutchins Street and Rose Street, wells screened at 70 to 80 feet bgs, 90 to 100 feet bgs, and 120 to 130 feet bgs 2) at Hutchins Street and Tokay Street, wells screened at 70 to 80 feet bgs, 90 to 100 feet bgs, 120 to 130 feet bgs, and 150 to 160 feet 3) in parking lot of the park at Hutchins Street and Vine Street, wells screened at 90 to 100 feet bgs, 120 to 130 feet bgs, 150 to 160 feet, and 170 to 180 feet; 4) on Lee Avenue south of Sierra (in line with York Street), wells screened at 90 to 100 feet bgs, 120 to 130 feet bgs, 150 to 160 feet, and 170 to 180 feet; The number, locations and depths of these wells may be changed during preparation of the plan and the installation of the initial wells, based on further review of existing well data and possible groundwater modeling, to meet the data needs and goals of the monitoring program. Task 21d Install Additional Wells Treadwell & Rollo will obtain appropriate permits for the wells (encroachment permits, well permits, etc.); notify Underground Services Alert (USA); contract with a private utility locater, a drilling contractor, and an analytical laboratory; and oversee installation of seven to eight well nests, or otherwise as determined during preparation of the Groundwater Monitoring Program Plan. The wells will be installed by sonic drilling technology and continuously logged for stratigraphic conditions. No soil samples will be collected. The wells will be developed after allowing adequate time for concrete to set around the well head. Drill cuttings and water generated by construction and development of the wells will be placed in 55 -gallon drums and stored in a location selected by the City, sampled and disposed as appropriate. Boring logs and well construction logs will be prepared for submittal to the City and the RWQCB. The wells will be surveyed by City GPS and well data up -loaded to the state "Geotracker"web database. Task 21e Perform Initial Round of Monitoring and Reporting Groundwaterfrom an estimated 7 existing wells and 24 depth intervals in the 7 new nested wells will be sampled for a period of one year on a quarterly or semi-annual basis. Results will be reviewed with the RWQCBto affirm the monitoring plan approach. TASK 22 NORTHERN PLUME STRATEGY The Northern Plume is the least -defined of the Lodi groundwater plumes. Work performed by the potentially responsible parties group included the construction of as many as 20 monitoring wells and approximately 50 borings to collect grab groundwater samples, with that work indicating the presence of VOCs at depths up to 400 ft bgs. The down -gradient extent of the Northern plume is not yet fully defined but is to at least as far south as Elm Street. There is also evidence the plume flows under the eastern portion of the Central Plume, a fact which may impact future groundwater remediation approaches to both plumes. The current condition of existing groundwater monitoring wells in the Northern Plume is not known and these wells will need to be evaluated with respect to location, screened Mr F. Wally Sandelin City Hall Public Works Department 2 July 2010 Page 5 intervals and well condition to determine if they would be useful for continued use. As these wells tend to be shallow, their utility in monitoring the overall extent of the Northern Plume is likely minimal. As part of the City's settlement with LusterCal, LusterCal maintains responsibility for mitigating soil contamination at their site, and the City is responsiblefor groundwater remediation. Initial discussions with LusterCal representatives have included the possibility of jointly funding a monitoring well near the southern boundary of the LusterCal property, but no progress has been made on that issue. As the City is the sole responsible party for the mitigation of the Northern Plume groundwater, the following steps for defining the groundwater situation are as follows: Task 22a Prepare Data Summary Treadwell & Rollo will prepare a summary document that includes all pertinent work performed to date (including all work at the LusterCal site) on the lateral and vertical extent of the groundwater contamination. This document will provide the basis for determining what additional work may be needed to define the plume, and where permanent groundwater monitoring wells should be located. Task 22b Groundwater Model Review Treadwell & Rollo will review the City-wide groundwater model and determine if rerunning the model with current groundwater elevation and chemistry data will significantly improve the summary document. We have assumed that a limited amount of modeling will be performed. Task 22c Meeting with LusterCal Treadwell & Rollo will meet with representatives of LusterCal and finalize how they and the City will go forward with cooperatively determining appropriate groundwater monitoring at and in close proximity to their site. Task 22d Groundwater Monitoring Plan Treadwell & Rollo will prepare an outline of a groundwater monitoring plan to take to the RWQCBthat allows monitoring the Northern Plume in sufficient detail to define its extent and its geographic overlap with the Central Plume. Based on the results of the data and modeling reviews, the plan will also identify additional monitoring wells that should be installed to effectively monitor the plume. Treadwell & Rollo will meet with the RWQCBto present the plan and determine an acceptable monitoring program. Task 22e Design Additional Monitoring Wells Treadwell & Rollo will prepare monitoring well designs for the proposed additional wells recommended and approved in the plan. For this proposal, we have assumed the installation of three to five well nests, each with wells screened to sample three to four groundwater horizons up to an expected maximum depth of 400 feet bgs. Not all additional wells may be constructed to this depth. The number and construction parameters for these wells will be determined during development of the monitoring program. Mr. F. Wally Sandelin City Hall Public Works Department 2 July 2010 Page 6 Task 22f Install Additional Wells Treadwell & Rollo will obtain appropriate permits for the wells (encroachment permits, well permits, etc.),- notify tc.);notify Underground Services Alert (USA); contract with a private utility locater, a drilling contractor, and an analytical laboratory; and oversee installation of the well nests, or otherwise as determined during preparation of the Groundwater Monitoring Program Plan. The wells will be installed by sonic drilling technology and continuously logged for stratigraphic conditions. No soil samples will be collected. The wells will be developed after allowing adequate time for concrete to set around the well head. Drill cuttings and water generated by construction and development of the wells will be placed in 55 -gallon drums and stored in a location selected by the City, sampled and disposed as appropriate. Boring logs and well construction logs will be prepared for submittal to the City and the RWQCB. The wells will be surveyed by City GPS and well data up -loaded to the state "Geotracker"web database. Task 229 Perform Initial Round of Monitoringand Reporting Groundwater from the depth intervals in the new nested wells will be sampled for a period of one year on a quarterly or semi-annual basis, as specified in Groundwater Monitoring the at a schedule to be determined. A range of costs are provided below due to the uncertainty of the number and design of the wells. Whether groundwater remediation is needed for the Northern Plume and how that remediation may impact Central Plume activities can be addressed when monitoring data is collected and evaluated. DRAFT SCHEDULE Below we present a draft schedule to assist the City in planning for this work. We can begin work within two weeks of receiving authorization. Our schedule for completion of the tasks will depend partly on the review periods required by the City and RWQCB and how quickly the City wishes to proceed. Allowing for a two-week review period for the City and a 30 -day review period for the RWQCB for the Groundwater Monitoring Program Plan and one week each for acceptance of responses to comments, we anticipate the following schedule. Task 21 Groundwater Monitoring Program 21a Southern Plume Data Collection Kickoff meeting with City Present Technical Memorandum to RWQCB Mobilize and Sample Groundwater Item Performance/Completion (week after receiving authorization) 21b Groundwater Monitoring Program Plan Submit Draft Monitoring Plan to City Receive Comments from City Draft Plan Presented/Submitted to RWQCB Receive Comments from RWQCB Response to Comments to RWQCB and Communication Week 2 Week 3 Week 5 Week 7 Week 8 Week 9 Week 14 Week 15 Mr. F Wally Sandelin City Hall Public Works Department 2 July 2010 Page 7 Task Item Performance/Comyietion Presented Plan to RWQCB (week after receiving authorization) 21b Groundwater Monitoring Program Plan (continued) Submit Final Plan to City Week 15 Receive Comments from City Week 15 Submit Final Plan to RWQCB Week 15 Receive RWQCB Approval Week 17 21c Design Additional Monitoring Wells Prepare well design Week 15 Submit well designs to City Week 15 Receive City comments on well designs Week 17 Select contractors Week 22 21 d Install Additional Monitoring Wells Obtain permits, mark locationsfor USA, private utility locater Week 22-25 Mobilize, install/develop wells, demobilize Weeks 26-30 Submitwell installation report Week 32 21 a Perform One Year of Monitoring and Reporting Third quarter 2010 through second quarter 2011 22 Northern Plume Strategy 22a Prepare Data Summary Kickoff meeting with City Week 2 Present Data Summary Documentto City Week 4 22b Groundwater Model Review Kickoff meeting with City Week 2 Present Modeling Results to City Week 6 22c Meeting with LusterCal Meeting Week 4 22d Groundwater Monitoring Plan Submit Draft Outline to City Week 7 Presented Plan to RWQCB Week 9 22e Design Additional Monitoring Wells Preparewell design Week 10 Submit well designs to City Week 10 Receive City comments on well designs Week 11 Bid out well designs Week 12 Select contractor Week 12 1♦ 1 1 Mr. F Wally Sandelin City Hall Public Works Department 2 July 2010 Page 8 Task Item Performance/Completion (week after receiving authorization) 22f Install Additional Monitoring Wells Obtain permits, mark locationsfor LISA, private utility locater Week 13 Mobilize, install/develop wells, demobilize Weeks 14 - 15 Submit well installation report Week 17 22g Perform One Year of Groundwater Monitoring and Reporting Third quarter 2010 through second quarter 2011 Note that the schedule given above is the span of time likely required to complete the work in and not a representation of total labor hours. ESTIMATED FEES We propose to perform our services on a time -and -expense, not to exceed basis in accordance with the City of Lodi Master Services Agreement. We estimate our fee to complete all the tasks described in this proposal will be $326,400 to $446,400, as detailed below. Task 21 Groundwater Monitoring Program, Southern and South Central/ Western Plumes Task 21a Southern Plume Data Collection ............................................... $41,200 Task 21b Prepare Monitoring Program Plan ............................................. $11,200 Task 21c Design Additional Monitoring Wells ........................................... $4,500 Task 21d Install Additional Monitoring Wells Estimated costs $125,000 to $175,000 Task 21e Perform One Year of Monitoring and Reporting (Based on $20,000 to $25,000 per event) Estimated costs of $80.000 to $100.000 Subtotal Task29 $26.1, 900 to 33X, 900 Task 22 Northern Plume Strategy Task 22a Prepare Summary Document ................................................... $10,000 Task 22b Perform Groundwater Modeling $10,000 - $25,000 Task 22c LusterCal Meeting and Planned Sessions .................................. $3,000 Task 22d Prepare Monitoring Plan (includes RWQCB meeting) ................. $7,000 Task 22e Design Additional Monitoring Wells ........................................... $4,500 Task 22f Well Installation Install Additional Monitoring Wells Estimated costs To be determined Mr. F. Wally Sandelin City Hall Public Works Department 2 July 2010 Page 9 Task 229 Perform One Year of Monitoring and Reporting (Based on $7,500 to $16,250 per event) Estimated costs of Subtotal Task22 PROJECT TOTAL $30.000 to 65.000 $64,500 to 114,500 $326,400 to 446,400 We appreciate the opportunityto present this proposal and look forward to assisting you on this project. Ifyou have any questions, please contact either Grover Buhr at asbuhr(cDtreedwellrollo.com or (510) 874- 4500, extension 529 or Phil Smith at pgsmit110)treadwellrollo.com or 415-955-9040. Sincerely yours, TREADWELL & ROLLO, INC. Grover Buhr, PG Senior Associate P0906402.OAK Philip G. Smith, REA II Vice President Attachment: Location of Southern and South Central/Western Plume Areas -- v�M-01G04 M W-1366 N MW -08 MW-19BB 9 G-07 O- � MW-0MW-09136. - 5j 'G -15A OMW-1066 MW -26D G-05 G-08 - G-06- G-12 MW-12BB G 10 ��J/// 16A MW -0566 MW-14BB G -19A G Well -03R �,.q7A24G-246G-11 —MW -0666 G -18G --- G-16BG-186 - ,G -18A G-13 G -16C Well -03 . MW-15BB — -- Q - MW- 1766 _ _ MW -12 G \ G -17A - _ MW -1666 MW -13 dI \ I, '/5 \MW \ MW -25C ! MW -1868 50 \1 50 100 \\ \ \\ 11.. ►I --I 1- 1 \ G-25 MW -24B MW -24C 1 I 1 \! 50 5 B G -25C 1' MW -24A 5 I i 100 1 & G -25A -. \- Tol<ay St 1 \ 1 1 MW -15 South Central/Western Plume I I 1 I \ I MW -21A PCP -4 -- \ - I Vine St - -- MW -216 - \ -- -- -- MW -21C \ MW -17 -- - �. MW -226 \ - Sierra Vista Place / - MW -22C MW -16 York St ♦ ♦ - MW -27D - - MW -23C MW -18 MW -23B `—Well -06R Park St (DSA -9,,\ SA - SA -1 A -SA 1 \ -SQA-? I Q � \ 50 \ ,\ Southern Plume.I MW -19 5 -SA-8 \ \ 1 rc. I SA -4 100 1j I \ SA31� �\ I' OS -01 / /SA; 6 / - - 0S-02 ' j ! ; 1 500 / / 1 Well -08 - Ke"Ieman Lane (Route 12) - \ _ ��. _- - - - ❑ I t\ SA -7 .0 / Well -12 'v G ❑ SA -10 i' 0 250 500 1,000 Feet Legend Treadwell & Rollo C:\GIS\3923\3923_22\arcmap_doc\3923-22-038.mxd MW -20 G• CITY OF LODI Lodi, California Elements cE Proposed Groundwater Monitoring Program,Southern and South CentralMestern Plumes Date 6/29/2010 Project No. 3923.31 T Figure 1 Tnka� Proposed Well South Western Central PCE Contours Monitoring Well - - Deep PCE Contour, Inferred ❑ City Water Supply Well Deep PCE Contour i Central Plume Monitoring Well _ _ _ Shallow PCE Contour, Inferred Railroad Shallow PCE Contour Park Southern Plume Contours Mokelumne River PCE +TCE + 1,1-DCE School Inferred Contour — Isoconcentration Contour Treadwell & Rollo C:\GIS\3923\3923_22\arcmap_doc\3923-22-038.mxd MW -20 G• CITY OF LODI Lodi, California Elements cE Proposed Groundwater Monitoring Program,Southern and South CentralMestern Plumes Date 6/29/2010 Project No. 3923.31 T Figure 1 Tnka� RESOLUTION NO. 2010-120 A RESOLUTION OF THE LODI CITY COUNCIL AUTHORIZING ADDITIONAL TASK ORDERS WITH TREADWELL & ROLLO FOR SOUTHERN, SOUTH CENTRALNVESTERNAND NORTHERN PCE/TCE PLUMES WORKPLAN PREPARATION AND MONITORINGAND FURTHERAPPROPRIATING FUNDS WHEREAS, staff and the consultants are moving forward on the implementation of Central Plume Interim Remedial Measures, including the construction of two groundwater extraction and nine soil vapor extraction wells and treatment facilities, and it is now time to move forward on remediation actions for the Southern, South Central/Western, and Northern Plumes; and WHEREAS, the goal of the Southern and South Central/Western Plume monitoring is to demonstrate the relative stability of the plumes and to establish that active groundwater remediation will not be needed to mitigate groundwater contamination associated with the plumes. Monitored natural attenuation would be accepted by the Central Valley Regional Water Quality Control Board as the remedy if groundwater monitoring validates that the plumes are stable and/or shrinking; and WHEREAS, the Northern Plume has not been as extensively studied, and the nature of this plume needs to be more extensively defined with respect to its lateral extent, general chemistry, and contaminant/depth relationships; and WHEREAS, proposed Task Orders No. 21 and 22 provide for the preparation of two workplans for review/approval by the Regional Water Quality Control Board (RWQCB), construction of monitoring wells, monitoring, and reporting to the RWQCB for up to one year; and WHEREAS, the estimated cost for Task Orders No. 21 and 22 is $446,400. NOW, THEREFORE, BE IT RESOLVED that the Lodi City Council does hereby authorize an additional task order in the amount of $446,400 with Treadwell & Rollo, of Oakland, California, regarding PCE/TCE cleanup; and BE IT FURTHER RESOLVED that funds in the amount of $500,000 be appropriated from the PCE/TCE Rates for these task orders. Dated: July 21, 2010 ------------------------------------------------------------------------ ------------------------------------------------------------------------ I hereby certify that Resolution No. 2010-120 was passed and adopted by the City Council of the City of Lodi in a regular meeting held July 21, 2010, by the following vote: AYES: COUNCIL MEMBERS — Hansen, Hitchcock, Johnson, Mounce, and Mayor Katzakian NOES: COUNCIL MEMBERS — None ABSENT: COUNCIL MEMBERS — None ABSTAIN: COUNCIL MEMBERS— None N OHL C1 y Clerk 2010-120