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HomeMy WebLinkAboutAgenda Report - August 19, 2020 C-04AGENDA ITEM c-4 Crrv or Loor CouNcrr CovrMUNrcATroN IM AGENDA TITLE: MEETING DATE: PREPARED BY: Approve Plans and Specifications and Authorize Advertisement for Bids for Central Plume PCE/TCE Groundwater and Soil Vapor Extraction System Decommissioning and Removal August 19,2020 Public Works Director RECOMMENDED ACTION Approve plans and specifications and authorize advertisement for bids for Central Plume PCE/TCE Groundwater and SoilVapor Extraction System Decommissioning and Removal. BACKGROUND INFORMATION: Historical practices have resulted in the contamination of groundwater by tetrachloroethylene (PCE) and trichloroethylene (TCE) producing four identified groundwater contaminant plumes (Northern, Southern, Central, and Western) within the City of Lodi. Efforts to remove PCE and related contaminants from the Central Plume Source Area (CPSA), have been ongoing since 2003, utilizing both soil vapor extraction (SVE) and groundwater extraction (GWE) systems. To date, the operation of the current SVE/GWE systems has contributed to the removal of approximately 20,000 pounds of PCE since operation began in 2011. On May 18,2020, the Central Valley Regional Water Quality Control Board (CVRWQCB) approved the City's recommended approach for decommissioning the CPSA remediation systems. Obtaining State approval to decommission these systems with the CSPA is a substantial step forward in the City's overall PCE/TCE cleanup program. On July 15,2020, Council authorized Amendment No. 3 to the Professional Services Agreement with Civil Hydro Tech, LLC for preparing plans and specifications and project management to carry out the closure and decommissioning, in the amount of $157,500. This project includes decommissioning the CPSA SVE and the GWE systems located near the alleyway that lies between Pine Street and Oak Street, between Pleasant Avenue and Church Street, as shown on Exhibit A. The work for this includes the following: Decommissioning and removal of the CPSA remedial systems including all on-site granular activated carbon vessels/tanks, concrete pad, above-ground piping and valves, and the treatment system enclosure; Removal of all underground piping associated with the CPSA remedial systems and the SVE and groundwater extraction wells that lie within property boundaries; Abandonment of the remedial piping within the City right of way; Abandonment of nine pairs of shallow and deep SVE wells, three pairs of vapor monitoring wells, and three groundwater extraction wells; a Removal of allwell vaults; APPROVED a a R:\GROUP\ADMIN\CouncilU020\08192020\Central Plume SVE System Closure\CPSA.doc ager a11312020 Approve Plans and Specifications and Authorize Advertisement for Bids for Central Plume PCE/TCE Groundwater and Soil Vapor Extraction System Decommissioning and Removal August 19,2020 Page 2 Excavation of the area near the intersection of alleyway and Pleasant Avenue, also shown on Exhibit A; Site restoration including street repair and other incidental and related work. This system was always anticipated to be removed when the treatment was no longer effective. As a requirement of the CVRWQCB, the City will need to provide notification and a fact sheet on PCE and TCE to all property owners in the vicinity. The specifìcations are on file in the Public Works Department. The planned bid opening date is September 16,2020. The project estimate is $250,000. Removal of this system will leave only two remaining City obligations in the Central Plume: 1) Operation of the groundwater extraction system at the toe of the plume, near Clyde W. Needham Elementary School, for an expected five to 10 year time frame, at an annual cost of approximately $150,000; and 2) groundwater monitoring for an expected 2}-year time frame, at an annual cost of $75,000. The PCE/TCE Fund is projected to have adequate funding to complete the remediation project. FISCAL IMPACT:Closure of the SVE/GWE system will signifìcantly reduce annual operating expenses; cost includes Granular Activated Carbon change-out. This work does not impact the General Fund. FUNDING AVAILABLE: Funding will be identified at project award Charles E. Swimley, Jr Public Works Director Prepared by Andrew Richle, Utilities Superintendent CES/AR/tc Attachment cc: Lyman Chang, Deputy Public Works Director Gary Wiman, Project Manager a a R:\GROUP\ADMIN\Council\2020\081 92020\Central Plume SVE System Closure\CPSA.doc 811312020 EXHIBIT A SVE AND GWE SYSTEM DECOMISSIONING AND REMOVAL