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HomeMy WebLinkAboutFull Tetra1 Commission Memorandum REPORT TO: Honorable Mayor and City Commission FROM: Dustin Johnson, Project Engineer Debbie Arkell, Director of Public Services SUBJECT: Amendment to Professional Services Agreement with Tetra Tech Inc. for Installation of an additional methane monitoring point MEETING DATE: September 12, 2011 AGENDA ITEM TYPE: Consent RECOMMENDATION: Authorize City Manager to sign the Amendment to Professional Services Agreement with Tetra Tech Inc. for installation of an additional methane monitoring point in the amount of $2,908.00 BACKGROUND: The City of Bozeman has been required by the Montana Department of Environmental Quality (DEQ) to sample and monitor the environmental effects of the Story Mill Landfill since 1994. Tetra Tech (previously Maxim Technologies) has been contracted with the City to assist in the work from the beginning. The nature of the contract has been to assist the City of Bozeman in sampling, maintaining, and monitoring post closure parameters at the Story Mill Landfill to keep the landfill in compliance with State and Federal regulations. On June 6, 2011 the City Commission approved an amendment to the professional services agreement with Tetra Tech that included: Upgrade and conduct maintenance of Landfill Gas Extraction (LGE) Wellheads, Preliminary Vapor Intrusion Evaluation, Monitoring Well Installation and Additional Monitoring. These items were considered general operations and maintenance issues and approved by the DEQ. The total price of the June 6th amendment was $22,334 and came out of the solid waste post closure fund. Since the June 6th amendment the DEQ has requested that an additional methane monitoring point be drilled on the landfill property. Two existing methane monitoring points (BLG-1 and BLG-4) have shown elevated levels of methane. Tetra Tech thinks the high levels of methane in BLG-1 can be corrected with adjustment of the landfill gas extraction flare, and has already had great success reducing the levels of methane. BLG-4 however has shown evidence of blockage in the probe itself. This blockage is preventing the free flow of methane through the screen. The thought is to drill a new well in the vicinity of BLG-4 to demonstrate that there aren’t high levels of methane, merely a faulty monitoring point. 2 The new monitoring point will then be sampled monthly with the other 15 monitoring points located at the landfill. If the new monitoring point demonstrates that there are no high levels of methane anywhere at the landfill, the city would pursue abandoning BLG-4 and sampling would be reduced to quarterly as it was before these elevated levels of methane were discovered. UNRESOLVED ISSUES: None. ALTERNATIVES: As suggested by the City Commission. FISCAL EFFECTS: With the project management, reporting, and data analysis, the total cost of this task order is $2,908. The entire project will be funded through the Solid Waste Landfill Closure/Post-Closure Fund. This fund is required by the DEQ to be maintained to ensure there are adequate funds for closure/post-closure activities required at landfills. There is currently $ 1,663,151.72 in this fund. Attachments: Tetra Tech Task Order/Proposal Report compiled on: August 29, 2011 Tetra Tech Page 1 of 2 851 Bridger Dr., Ste 6 Bozeman, Montana 59715 Office: (406) 582-8780 TASK ORDER / PROPOSAL CORRECTIVE ACTION TO ADDRESS METHANE EXCEEDANCES IN METHANE MONITORING POINTS BLG-1 AND BLG-4 BOZEMAN SANITARY LANDFILL August 23, 2011 CLIENT: CONSULTANT: The City of Bozeman Tetra Tech, Inc. P.O. Box 1230 851 Bridger Drive, Ste 6 Bozeman, Montana 59711-1230 Bozeman, MT 59715 Attention: Mr. Dustin Johnson Attention: Mr. Mark F. Pearson This task order/proposal is presented to the City of Bozeman in response to the May 18, 2011 DEQ correspondence requesting additional corrective measures be undertaken to address methane exceedances in methane monitoring points BLG-1 and BLG-4. Methane exceedances in point BLG-1 will be addressed in an additional modification of the well head in the closest landfill gas extraction (LGE) well GW-10 in accordance with a previous task order. Specifically, the flexible pipe installed on LGE well GW-10 wellhead will be shortened and re-oriented to prevent the accumulation of condensate (in the flexible piping) from blocking gas extraction. Methane exceedances in point BLG-4 will be addressed by installing an additional methane monitoring point south of BLG-4, adjacent to the south property boundary of the landfill (or approximately 17 feet south of BLG-4). Methane/landfill gas monitoring will then be conducted in the new methane monitoring point. Therefore, the following tasks are proposed: SCOPE OF SERVICES: TASK 1 - INSTALL ADDITIONAL METHANE MONITORING POINT Tetra Tech proposes to subcontract JBR Environmental (JBR) to install one methane monitoring point approximately 8.5 feet south of the existing methane monitoring point BLG-4. JBR was solicited for bid in consideration of installing the additional point proximal to a power line that exists along the south boundary of the landfill. JBR will use a Geoprobe to “direct-push” the hole to a depth of 25 feet. The Geoprobe was selected because its mast height (13 feet) is less than that of a conventional drilling rig (about 25 feet) and therefore, can safely be closer to the power lines. Underground utilities will be cleared prior to drilling using the ‘one-call’ underground utility locate service. It is assumed a custom utility locate (at additional cost) will not be necessary. Drill cuttings will be examined and described by a Tetra Tech soil scientist or geologist. Well completion will consist of installing 1-inch outer-diameter (OD) and 3/4-inch inner-diameter (ID), Schedule 40, polyvinyl chloride (PVC) piping (slotted and blank) to a depth of 25 feet. Approximately 20 feet of slotted PVC piping will be used. The borehole will be backfilled with 10-20 silica sand around the slotted PVC interval and bentonite to the surface. The bentonite will be hydrated as it is being placed above the silica sand interval. The PVC well will be protected by steel casing with a locking cap. The steel casing will be secured with a concrete grout. The one-inch well will be fitted with an air-tight, barbed valve to allow for gas monitoring. Tetra Tech Page 2 of 2 851 Bridger Dr., Ste 6 Bozeman, Montana 59715 Office: (406) 582-8780 TASK 2 - PROJECT MANAGEMENT AND REPORTING It is expected that equilibrium conditions can be achieved within fourteen days after completion of the new methane monitoring point. After this time period, landfill gas monitoring will be conducted. Results will be included in a brief letter report to City of Bozeman and DEQ citing the well installation activity, monitoring results, and well log. The report to City of Bozeman and DEQ will also include the date of completion of the modification of well GW-10. PERIOD OF PERFORMANCE: Activities covered in this task order will begin upon approval of this task order and are anticipated to be completed by September 30, 2011. A brief report will be submitted to City of Bozeman and DEQ within three working days after monitoring of the new methane monitoring point has been conducted. COMPENSATION: Estimated costs to complete the foregoing scope of services are not to exceed $2,908. Attachment A details these costs. All services in this task order will be conducted on a time and materials basis. SPECIAL CONDITIONS: Execution of this Task Order constitutes acceptance of all terms and conditions contained in Tetra Tech’s Professional Services Agreement with the City of Bozeman, dated January 3, 1994 and Amendment Nos. 1, 2, 3, and 4 of the Professional Services Agreement dated July 31, 1995; January 1, 1996; March 17, 1997; and December 10, 2001, respectively. CLIENT: CONSULTANT: City of Bozeman Tetra Tech By: By: Its: Its: Date: Date: NOTICE OF CONFIDENTIALITY This Task Order (including attachments) contains information confidential to Tetra Tech, Inc., its subsidiaries, and subcontractors. It is intended only for City of Bozeman to consider Tetra Tech providing professional services at the Bozeman Landfill. Any other use is prohibited, without the prior written consent of Tetra Tech. Task 1 INSTALL ADDITIONAL METHANE MONITORING POINT Units Unit Cost Amount JBR Environmental Methane Monitoring Point Completion Quote 1 $1,975 $1,975 Tetra Tech Project Manager / Hydrogeologist, per hour 7 $85 $595 Tetra Tech markup of 10% (of subcontractor time and materials) $198 SUBTOTAL $2,768 Task 2 PROJECT MANAGEMENT AND REPORTING Units Unit Cost Amount Tetra Tech Project Manager / Hydrogeologist, per hour 1 $85 $85 Clerical or Administrative Assistant, per hour 1 $55 $55 SUBTOTAL $140 TOTAL $2,908 CORRECTIVE ACTION TO ADDRESS METHANE EXCEEDANCES IN METHANE MONITORING POINTS BLG-1 AND BLG-4 ATTACHMENT A BOZEMAN SANITARY LANDFILL August 23, 2011 August 23, 2011 Tetra Tech Page 1 of 1