HomeMy WebLinkAboutItem 10 - Minters Chapel Road ConstructionMEMO TO:
FROM:
MEETING DATE:
SUBJECT:
RECOMMENDATION:
ITEM it
HONORABLE MAYOR AND MEMBERS OF THE CITY COUNCIL
ROGER NELSON, CITY MANAGER�/t)
FEBRUARY 5, 2002
PROFESSIONAL SERVICES CONTRACT APPROVAL — IT
CORPORATION — MINTERS CHAPEL ROAD CONSTRUCTION
City Council consider ratifying Professional Services Contracts with IT Corporation for
environmental assessment services relative to the Minters Chapel Road Construction
Project in a combined amount of $ 31,812.30, and take any necessary action.
FUNDING SOURCE:
Funds are available in the 99 GO Bonds, account number 178-78102-010.
BACKGROUND:
i The Minters Chapel Road Project has been a very complicated project to develop due to
the Hexavalent Chromium soil and groundwater contamination from the AGT site on the
west side of Minters Chapel Road. Remediation of this contamination has been ongoing
by AGT for at least 10 years under the guidance of the TNRCC.
The project included water, wastewater and storm drainage lines in Minters Chapel
Road to be constructed through the contamination plume north of Cottonwood Branch.
The potential issues facing us because of this work in contaminated soil and
groundwater required close coordination with AGT, their consultant, TNRCC, and
surrounding property owners. Staff had no experience with this type of contamination
and needed a consultant experienced in contamination and remediation issues as well
as TNRCC procedures.
Staff initially engaged IT Corporation in November 1999 to provide professional
consultation services regarding the development of construction plans for the Minters
Chapel Road Project. The known contamination extended from the AGT facility on the
west side of Minters Chapel Road southeast across the roadway to Cottonwood Branch.
IT Corporation advised the Staff on a variety of contamination issues, including meeting
with TNRCC Staff, as the plans for the construction were developed. They also provided
a Groundwater Handling Plan and a Soils Handling Plan for inclusion in the contract
documents which stipulated how the contractor was to address contaminated soil and
groundwater when encountered.
January 25, 2002 (3:15PM)
This initial contract for $ 2,500 was amended several times between the initial date and
12/6/01 to provide continued consultation services as this project was developed with a
total cost of $ 13,678.30.
In addition to the professional consultation services, Staff also engaged IT Corporation
for two additional tasks. IT, at the City Staff's request, hired and coordinated the efforts
of a third party sampling and testing firm to take soil samples and perform chromium
analysis of the soils samples to ascertain the existing levels of chromium contamination
in the soils. The samples were taken both from beneath Minters Chapel Road north of
Cottonwood Branch and in Cottonwood Branch downstream of Minters Chapel Road,
where the contamination plume was known to exist. The cost for this task was
$ 14,214.00.
Finally, Staff engaged IT Corporation to hire a firm to take soil borings in Minters Chapel
Road to accurately determine the depth of the confining sandstone layer beneath the
pavement. Through the contamination plume area beneath Minters Chapel Road, the
construction plans reflected storm drainage, water and wastewater lines at a depth near
the top of the sandstone layer. This sandstone layer effectively provides a lower sealed
floor above which the chromium contaminated groundwater is contained. Insuring that
the proposed construction would not breach this sealing sandstone layer is critical for
the success of this project. If the sandstone layer is breached, ground water beneath
this level could be contaminated. To protect the City and the contractor, we had to have
an accurate representation of the upper limit of the sandstone layer. The cost for this
activity was $ 3,920.00
While each contract with IT Corporation involved a separate scope of work, all three did
involve the Minters Chapel Road Project.
Staff recommends approval.
JLH/JSL/jdr
OAAGENOAM-05-02VT Contract Ratification
January 29, 2002 (8:34AM)