A geochemical investigation was conducted for a regional telephone company
by Exploration Technologies, Inc. ("ETI") in the vicinity of the
buried telephone right-of-way. For this study, water samples and ambient
air samples were collected from within telephone conduit manholes at and
near the Site. Additionally, air samples were collected from the pressurized
phone line cables within two of these manholes. Some four foot deep and
some seven foot deep soil vapor samples were collected using ETI's proprietary
sampling techniques.
Survey sample placement was guided by four objectives: (1) verify the
existence of gasoline contamination reported in the telephone conduit
manhole; (2) determine if contamination is present in other manholes that
are located along the cable conduit run; (3) establish whether a gasoline
station located nearby is the source of the gasoline reported at the Site
and (4) assess the possibility of gasoline being pooled under the highway
where the telephone cable run extends between two manholes.
Analytical results include measurement of the light hydrocarbons in the
methane through butane (C1-C4) range as well as the gasoline (C5+) range
hydrocarbons. Concentration maps were prepared to illustrate the horizontal
distributions for methane, ethane, propane, normal-butane and C5+ gasoline
range hydrocarbons from the soil vapor samples. The maps, plus data derived
from the water, ambient air, and pressurized phone line cables, leads
to the following site characterization conclusions:
(a) Gasoline and its associated vapors
are clearly present.
(b) The service station north of the Site
appears to be the source of gasoline contamination found in this manhole.
(c) There is a good possibility that gasoline
contamination exists under the highway near where the telephone cable
run crosses this major traffic artery.
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