HomeMy WebLinkAboutAmendment to Professional Services Agreement with Tetra Tech for post-closure soil gas investigation at Story Mill Landfill Commission Memorandum
REPORT TO: Honorable Mayor and City Commission
FROM: Craig Woolard, Public Works Director
Dustin Johnson, Project Engineer
SUBJECT: Amendment to Professional Services Agreement with Tetra Tech Inc. for post-closure soil gas investigation at the Story Mill Landfill.
MEETING DATE: March 18, 2013
AGENDA ITEM TYPE: Consent
RECOMMENDATION: Authorize City Manager to sign.
BACKGROUND: Since the City of Bozeman has been required by the Montana Department
of Environmental Quality (DEQ) to monitor the environmental impacts of the Story Mill Landfill Tetra Tech (previously Maxim Technologies) has been contracted with the City to serve as a consultant. The nature of the contract has been to provide consulting services to the City of
Bozeman in the form of sampling, drafting technical reports to the DEQ, and keeping the landfill
in compliance with State and Federal regulations.
Historic sampling of groundwater in and around the landfill have found various levels of volatile organic compounds (VOCs). All samples taken outside the limits of the landfill property
are currently within the groundwater protection standards (GPS). Groundwater sampling is
required by the DEQ twice each year. Unfortunately, VOCs can be transported in groundwater
and in soil gas. Groundwater sampling data alone is not providing enough information as the City attempts to better understand the decomposition of the Story Mill Landfill.
Previously, Tetra Tech used existing gas monitoring wells located on the landfill property
to measure the VOCs in soil vapor. The results of these tests were inconclusive and their
recommendation was to move farther away from the landfill itself. The attached task order outlines a process in which Tetra Tech and a sub-consultant will
install Geoprobes in the rights of way of Caddie Court, Turnberry Court, and St. Andrews Drive
in the neighboring subdivision. These new geoprobes will be used to monitor the soil vapor in
the area. The information gained from this investigation will be used to assess the potential for gas (vapor) intrusion to occur in residential structures in the subject neighborhood.
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Included with this task order is the preparation of a neighborhood communication plan.
A flyer would be drafted and placed on each residence’s door on the streets identified above.
This flyer would explain when the sampling event will take place, what the purpose of the
sampling is, and will provide necessary contact information for both the consultants and the City of Bozeman.
The proposed cost for this task order is $25,933. Included in this task order are extra
labor hours in the event that extra service time is required to troubleshoot something at the
landfill or additional data analysis is required. FISCAL EFFECTS: The entire project will be funded through the Solid Waste Landfill
Closure/Post-Closure Fund.
ALTERNATIVES: As suggested by the City Commission.
Attachments: Task Order from Tetra Tech Inc.
Report compiled on: 2/27/13
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