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APPROVE MOTION TO AUTHORIZE CONTRACT AMENDMENT THREE WITH TERRAPHASE ENGINEERING FOR ENVIRONMENTAL ASSESSMENT AND PATH TO CLOSURE SERVICES AT 130 NORTH HUNTER STREET
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RECOMMENDATION
It is recommended that the City Council approve a motion to:
1. Authorize Amendment Three with Terraphase Engineering in the amount of $179,750.80 for environmental assessment and path to closure services at 130 North Hunter Street; and
2. Authorize the City Manager, or designee, to take necessary and appropriate actions to carry out the purpose and intent of this motion.
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Summary
The site at 130 North Hunter Street, known as Coy Garage, is an active case with the Central Valley Regional Water Quality Control Board (“Water Board”). The site contains a history of contaminated releases through a Leaking Underground Storage Tank (“LUST”) that requires an investigation to be performed to ascertain the level of contamination in the groundwater and to develop a path to regulatory closure with the Water Board.
On October 17, 2023, City Council authorized by Motion 2023-10-17-1206 a contract with Terraphase Engineering, Inc. to update the investigation work plan, conduct the field work activities, coordinate with the Water Board, and seek regulatory closure through the preparation of a results report for the City-owned property located at 130 North Hunter Street (Attachment A - Contract 424000208).
Since contract execution, EDD staff and Terraphase have engaged with representatives from the Water Board regarding the work plan and investigation requirements, with the Water Board approving the work plan in August 2024. Due to cost escalations from inflation, the number and depth of soil borings requested by the Water Board, and the field work taking place at night to avoid disruption to Coy Garage, it was determined that inadequate funding was available to commence field work.
Staff are requesting approval of contract amendment three to mobilize the investigation at 130 North Hunter Street and seek regulatory closure with the Water Board.
DISCUSSION
Background
The 130 North Hunter Street site is the location of Coy Parking Garage. The site is a former San Joaquin County Motor Pool Facility that operated an underground storage tank (UST) system. An unauthorized release was reported in November 1994 following a site assessment. On August 13, 1996, Fisch Environmental removed two USTs and the associated piping and dispensers. According to the inspection notes, both tanks appeared corroded, and holes were observed in one of the USTs. Results of subsequent investigations indicated that soil and groundwater beneath the site had been impacted by petroleum hydrocarbons. Based on a review of communication from the Water Board, vapor intrusion does not pose a significant exposure concern due in part to the presence of a parking garage on the site. Instead, the focus of the field work is geared toward defining the nature and extent of the deeper groundwater contamination, which does not impact site safety in its current use.
As the owner of the site, the City of Stockton is considered the responsible party for conducting environmental investigation and seeking closure of the open case with the Water Board. Staff from the Economic Development Department (EDD) have been coordinating with Water Board staff on the completion of the work plan and commencing field activities over the past few years, but little progress could be made without contractors or funding in place.
In March 2023, the City published a Request for Proposals (RFP) for environmental support services, which included the preparation of a site assessment work plan and field work implementation at 130 North Hunter Street. With Council authorizing a contract with Terraphase Engineering in the amount of $180,211, a work plan for investigation activities was prepared and approved by the Water Board.
Present Situation
The anticipated cost of the environmental investigation at 130 North Hunter Street exceeds the available budget. The Water Board has requested the City commence the field work as soon as possible and provide a results report for their review by October 30, 2025. Failure to perform these activities could result in further regulatory actions that would impact the City’s ability to operate the site under its current use.
Due to the extent of site investigation work requested by the Water Board, staff is seeking approval of a contract amendment in the amount of $179,750.80 to implement the field work approved by the Water Board. Approval of contract amendment three would increase the not-to-exceed amount to $359,961.80 (Attachment B - Contract Amendment Three).
FINANCIAL SUMMARY
Budget authority to complete this work is $179,750.80 This contract will be funded with $111,000 of one-time discretionary funds, approved specifically for this work, through the FY 2024-25 Budget Development process, and appropriated to EDD’s General Fund. The remaining $68,750.80 will be paid out of EDD’s General Fund. There is sufficient budget to support this work.
Attachment A - Contract 424000208
Attachment B - Contract Amendment Three