Response No.                                      Response

         estimated that there is sufficient quality and quantity of material
to warrant salvage
         topsoil, and that rocks should not pose serious problems. Exxon'
s consultants (Foth-
         Van Dyke), obtained soils data from auger samples and projected
a mean topsoil depth
         9.8 inches. Exxon states in their reclamation plan that the upper
soils would be bet.
         use in reclamation than the lower soils and therefore would be stripped
and salvaged'

         The presence of stones would not pose insurmountable problems for
topsoil salvage .
         stockpiling. Larger fragments, rocks, and boulders could be used
as rip-rap, slope
         stabilization or crushed for gravel. While certain areas may contain
localized
         concentrations of rocks, few problems are anticipated regarding
topsoil salvage and-
         stockpiling. Soils with coarse fragments may have productivity equal
to or greater
         premining soils. Numerous studies have demonstrated the beneficial
effects of stony
         mine soils, especially regarding reforestation.

   383   Under the worst case scenario and certain model assumption inputs,
the sulfate
         concentration at the compliance boundary in some aquifer units could
exceed the
         groundwater quality standard as explained on DEIS pages 111, 112
and 116-117. Most
         simulations, however, indicate the groundwater quality standard
for sulfate would not
         exceed 250 ppm at the compliance boundary, and would be substantially
less than that

   384   Comment acknowledged.

   385   Comment acknowledged.

   386   An explanation of areas potentially requiring special erosion control
(DEIS Fig. 1-18)i
         been added to the text. These are areas on the reclaimed MWDF where
rock rip-.rap X
         engineered water control structures would be needed.

   387   There will be no requirement for monitoring alkalinity in the wastewater
discharge.,
          However, alkalinity would be monitored in Swamp Creek as part of
the surface water
          quality monitoring program as shown on DEIS Table 1-14. Total hardness
is proposed
          monitored in both the discharge and in Swamp Creek.

   388 There would be an approximately one year (or more) lapse between the
granting of pe
          and start of construction, due to the need for Exxon to develop
and receive approval 3
          plan of operation, develop construction contracts, etc. We anticipate
no problems in t
          timely scheduling of mandatory, preconstruction environmental monitoring
elements.
          would be Exxon' s responsibility to comply with preconstruction
monitoring requireme
          order to receive subsequent approvals.

   389   Refer to response #388.

   390   The word, "uniformly', has been deleted from the text. The
point of the discussion is
          the wells are located spatially to provide coverage in all directions
from the MWDF a
          finished in the hydrostratigraphic units of most concern.

   391   It is believed that the proposed monitoring well configuration is
reasonable in its exten
          spatial and hydrogeologic orientation and coverage. The monitoring
locations were
          selected to provide a network capable of detecting migration of
contaminants away fo
          the waste facilities. The wells have been located within the hydrostratigraphic
units w
          would most readily transmit the contamination, and they are situated
spatially so that tt
          major flow directions during all phases of the project would be
adequately intercepted. 0.



392   Anomalies detected on the air photos would be followed with field investigations
to
      determine cause as explained on DEIS page 41. Systematic direct observation
(either by:
      or ground reconnaisance) to detect vegetation stresses does not seem
warranted as an
      explicit monitoring element. A high level of direct, daily observations
would be made by
      Exxon operations staff, as well as through Department staff oversight
of operations.



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