HomeMy WebLinkAboutMINUTES - 09121989 - 2.3 245-8901/B. 4
TO: y: BOARD OF SUPERVISORS
FROM: J. Michael Walford, Public Works Director Contra
Y September 12, 1989 CostaDATE: \/O^
SUBJECT: ABATEMENT OF SOIL AND GROUNDWATER CONTAMINATION OAT 99 BLANCHE
LANE, LAFAYETTE, CA (Authorization No. WH305A,B)
SPECIFIC REQUEST(S) OR RECOMMENDATION(S) & BACKGROUND AND JUSTIFICATION
I. RECOMMENDATION
FIND that an emergency exists and AUTHORIZE the Director of
General Services to proceed in the most expeditious manner,
pursuant to Public Contract Code Section 20134, to abate
contamination of soil and groundwater caused by leaking fuel
tanks at the Public Works Department corporation yard at 999
Blanche Lane, Lafayette, and DECLARE that the project, as an
emergency, is exempted from the provisions of the California
Environmental Quality Act under Section 15269(c) of the State
CEQA guidelines.
II. FINANCIAL IMPACT
Cost estimates for abatement of the soil contamination
are in the range of $200,000 to $300,000. Funding will be
from the Public Works Department. Some costs could be offset
if the services of IT Corporation can be used under the terms
of the recent settlement and consent decree with IT
Corporation.
III. REASONS FOR RECOMMENDATION/BACKGROUND
A. In late June 1988, tests indicated that an underground
fuel storage tank was leaking at the Public Works
corporation yard in Lafayette. Fuel deliveries were
discontinued and fuel was dispensed from the tank until
August 1988, when it was essentially empty. In April
1989, the two tanks at the site and surrounding
contaminated soil were removed.
B. On advice from the Health Services Department, a
consultant was retained to investigate the soil and
groundwater in the vicinity, after the tanks were
removed. According to the consultant' s report, dated
August 24 , 1989, "significant levels of gasoline are
present in soils and minor to moderate levels of gasoline
are present in the' groundwater. The contaminant plume
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RECOMMENDATION OF COUNTY ADMINISTRATOR RECOMMENDATION OF BOARD COMMITTEE
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ACTION OF BOARD ON S P APPROVED AS RECOMMENDED OTHER _
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I HEREBY CERTIFY THAT THIS IS A TRUE
UNANIMOUS (ABSENT AND CORRECT COPY OF AN ACTION TAKEN
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ABSENT: ABSTAIN: OF SUPERVISORS ON THE DATE SHOWN.
cc: General Services Department ATTESTED -_SEP I L 198
Architectural Division PHIL BATCHELOR, CLERK OF THE BOARD OF
Accounting SUPERVISORS AND COUNTY ADMINISTRATOR
County Administrator's Office
County Counsel ,
Auditor-Controller BY ,DEPUTY
M382/7-83
Public Works Department
exists in a two to three foot thick layer between 10 and
13 feet below ground level at the site. The downgradient
extent of the plume is up to 200 feet from the tankpit,
and up to 80 or 100 feet in width. "
C. Such contamination must be abated to comply with various
federal, state and local laws governing hazardous waste
and underground tanks.
D. In a report dated August 28, 1989, a groundwater
consultant has warned that, "Although the primary source
of gasoline contamination (underground tanks) has been
eliminated, further down-gradient migration of gasoline
contamination already in the soil can be expected to
occur during the next wet season, with at least low
concentrations of gasoline migrating beneath Mt. Diablo
Blvd. Due to the potential for migration of contaminated
groundwater into the highly permeable trenches of sewers,
storm drains, and other utilities, as well as the general
impracticability for conducting soil and groundwater
remediation within a major thoroughfare, it would be
prudent to remediate or in some way contain the
contamination prior to the next wet season. "
E. Subject to further engineering study and testing, the
abatement process will probably include the following:
(1) Removal and stockpiling of clean overburden to a
depth of 10 to 13 ft. , (2) removal of a 2 to 3 ft.
,layer (up to 3000 c.u. ) of contaminated soil. That
which exceeds contamination of 1000 PPM will be
aerated on site as required to lower contamination
to 1000 PPM or less. All contaminated soil will be
transported to County property near Imhoff Drive and
Blum Road in Martinez, for further aeration as
required to reduce contamination to levels approved
by County Environmental Health Division, ( 3)
replacement of contaminated soil which was removed
from the Lafayette site with clean fill obtained
from Siemens Medical Laboratory construction site on
Nelson Avenue, Concord, and ( 4) backfilling with the
stockpiled clean overburden.
F. Since there is not time to use the normal public bid and
construction process to abate the contaminated soil
before the wet season, it is necessary for the Board to
proceed on an emergency basis pursuant to Section 20134
of the Public Contract Code to avoid danger to the
environment and property in the vicinity.
24501B09.05A
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