AGENDA TITLE:
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Adopt a Resolution Authorizing Interim City Manager to Execute Amendment No. 8 to Professional Services Agreement with Civil Hydro Tech, LLC, of Sunnyvale, for Lodi Central Plume Area, Northern Plume, and City-Wide Plume Management Services ($506,900), and Appropriating Funds ($506,900) (PW)
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MEETING DATE:
April 3, 2024
PREPARED BY:
Public Works Director
recommendation
RECOMMENDED ACTION:
Adopt a Resolution Authorizing Interim City Manager to Execute Amendment No. 8 to Professional Services Agreement with Civil Hydro Tech, LLC, of Sunnyvale, for Lodi Central Plume Area, Northern Plume, and City-Wide Plume Management Services ($506,900), and Appropriating Funds ($506,900)
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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 monitor and remove PCE and related contaminants from the Central Plume Source Area (“CPSA”) have been ongoing since 2003, utilizing both soil vapor extraction and groundwater extraction systems. To date, the clean-up efforts have removed treatment systems and have resulted in the removal over 20,000 pounds of PCE and TCE. In addition to the mandated clean-up efforts the Central Valley Regional Water Quality Control Board (Water Board) requires the City to monitor the migration of the contaminant plumes through a network of groundwater monitoring wells under the current Monitoring and Reporting Order R5-2018-0800 issued by the Water Board in January 11, 2018.
The current contract with Civil Hydro Tech, LLC (“CHT”) is comprised of several amendments, with Amendment No. 6 and No. 7 outlined below to provide background and context for requesting approval of Amendment No. 8. Amendment No. 6 provided consulting and project management for ongoing investigation and remediation in two specific areas impacted by the central plume where the SVE system was unsuccessful in removing contaminants. As part of the State approved Central Plume Closure Plan, the City proposed that if indoor air monitoring indicated PCE concentrations above the Environmental Screening Level, due to remaining soil or soil vapor contamination, the City would perform additional investigative activities using passive soil gas (PSG) samplers and other sampling methods to pinpoint the area(s) of impacts, and targeted remediation. In addition, CHT was tasked with the abandonment of 21 monitoring wells removed from the revised Monitoring and Reporting Program (MRP) approved by the Water Board on January 29, 2024. These activities are ongoing. Amendment No. 7 was a continuation of annual Groundwater Monitoring, Sampling and Reporting services for the Lodi Plumes for sampling events through the first quarter of 2024.
The scope of work of Amendment No. 8 consists of performing additional soil vapor assessment within the CPSA, specifically in and around the properties of 210 and 212 W. Pine and Guild Cleaners ($86,900). Additional sampling will be conducted in the vicinity of 18 S. Pleasant Avenue to determine the extent of PCE in the soil. CHT will also perform a five-day sub-slab depressurization system pilot test in an effort to evaluate the effectiveness in removing residual PCE vapor at 212 W. Pine ($91,700). The pilot test results will be submitted to the Water Board. Following the completion of the assessment and based on the best remedial alternative, CHT, with approval from the Water Board, will prepare a Work Plan, which will include the design and implementation of a permanent depressurization system ($114,200).
Additional tasks proposed with Amendment No. 8 include a rebound study and closure report for the Mid-plume Groundwater Extraction Treatment System ($23,500); Northern Plume Closure Activities ($12,400); Additional subcontractor costs associated with monitoring well abandonments ($25,600); Project Management of City Sewer Main Replacement and Soil Excavation Activities (if warranted by soil vapor assessment $117,600); and on-call environmental services for city-wide plume management ($35,000).
Staff recommends authorizing Interim City Manager to execute Amendment No. 8 to Professional Services Agreement with Civil Hydro Tech (CHT), LLC, of Sunnyvale, for Lodi Central Plume Area, Northern Plume, and City-wide Plume management services, in the amount of $506,900 and appropriating funds in the amount of $506,900.
STRATEGIC VISION:
8. Public Well-Being.
FISCAL IMPACT:
The City is responsible for all cleanup and mitigation efforts associated with PCE/TCE as per Cleanup and Abatement Order No. R5-2004-0043 for the Central Plume Area. Failure to comply can result in fines.
FUNDING AVAILABLE:
Appropriation Request:
Central Plume Fund 590 (59099000.77020): $ 35,000
Northern Plume Fund 593 (59399000.77020): $ 12,400
PCE/TCE Rates Fund 565 (56599000.77020): $459,500
TOTAL: $506,900
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Charles E. Swimley
Public Works Director
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Melissa Munoz
Accounting Manager
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Jeff Berkheimer (for Andrew Keys)
Acting City Manager/Electric Utility Director