TABLE 1

LAKE SEEPAGES FROM DNR MODEL COMPARED TO REGIONAL RECHARGE



          Throughout this chapter (and consequently in subsequent ones too),
the
     DEIS presents an inconsistent and ultimately misleading picture of the
     Interaction between lakes and the ground water system. As a result,
the DEIS
     tends to downplay the significance of the possible impacts of pumping
on lakes
     near the mine site.

         The issue is whether Duck, Deep Hole, Little Sand, Oak and Skunk
Lakes are
     "perched" or whether they are "seepage" lakes. The
former means that the lake
     is essentially unconnected to the ground water system and thus largely
immune
     to ground water changes. The latter means that water from the lake flows
to
     the ground water system and increased pumpage of the ground water will
     generally cause a loss of water from the lake. Thus the latter type
of lake
     is susceptible to significant impact by a project such as Crandon.

         Historically, both the DNR and Exxon initially called all five lakes
     perched. Field measurements and water budget models by Wisconsin Geological
     and Natural History Survey, USGS, Dames & Moore, and DNR have all
shown that
     only Oak Lake, among the five in question, is perched. And, in fact,
the DEIS
     (on pps. 58-60) properly labels each of the lakes.

         My concern is that except for changing the labels, Chapter II persists
in
     interpreting all these lakes as perched and thus only slightly connected
to
   Xthe ground water system. Figure 2-6 shows a perched lake as typical even
'272)though Oak is the only one. Figure 2-4 implicitly treats all five lakes
as
perched because it shows no mounding of the water table beneath them.   
   The
     water table contours go right through these lakes, unaffected by their
     presence. In contrast, the contours at Ground Hemlock and Rolling Stone
Lakes
     are controlled by the lake. These latter lakes are ground water discharge
     lakes, and the originator of Fig. 2-4 has treated their surfaces as
extensions
     of the water table, while drawing the other five lakes as isolated from
the
     water table. This is clearly a bias, one that is not substantiated by
any
     field data, and one that is not fully understood by the writers of the
DEIS.

         This bias surfaces subtly throughout the remainder of the DEIS,
but always
     in a fashion which may mislead the reader on the impact of pumping on
the
lakes.       Perhaps the most blatant is on p. 52.    "Lakes and wetlands,
especially
(273)those perched [sic] above the regional water table, are constant but
minor
  "sources of recharge [to ground water]."     In fact, all the
lakes for which DNR
     itself has done a water budget model currently produce seepage recharge
in
     excess of 7.5 in/yr (Table 1). That recharge rate is the middle of the
5-10
     in/yr range quoted as normal in the Crandon Mine area. In other words,
the
     lakes produce ground water recharge at a greater rate than non-lake
areas and
     that cannot be dismissed as minor. Skunk and Deep Hole provide over
40 in/yr
     of recharge at present (Table 1). Even Exxon's consultants show that
all the
     lakes produce seepage at greater rates then 7.5 in/yr (Table 2). And
under
     their maximum impact conditions, the DNR shows that lake seepage rates
will
     exceed recharge by from three to seventy-five times!



Present Conditions



Maximum Impact



                  Seepage      Seepage/       Seepage      Seepage/
Lake               (in/yr)      Recharge       (On/yr)      Recharge

Duck               22.17          3.0           24.64          3.3

Deep Hole          45.25          6.0           76.93         10.3

Little Sand         8.20          1.1           67.8           9.0

Skunk             44.48           5.9          562            74.9

Note: Present and impact condition values use WDNR2 lake bed permeabilities;
impact assumes no ground water mounding. Recharge value is taken to be 7.5
in/yr, the average rate quoted in the DEIS. Lake areas from DNR model.



Lake



                       TABLE 2

    PRESENT LAKE SEEPAGES FROM EXXON CONSULTANTS
            COMPARED TO REGIONAL RECHARGE

IT Model Using WDNR2   Dames & Moore Water Budget

    Seepage      Seepage/       Seepage      Seepage/
    (in/yr)      Recharge       (in/yr)      Recharge



     Duck               22.00          2.9           18.60          2.5

     Deep Hole         40.82           5.4            8.75          1.2

     Little Sand        8.54           1.1            8.51          1.1

     Skunk               7.65          1.0          127.8          17.1

     Note:  IT results from GEOFLOW using WDNR2 permeabilities.   Recharge
value is
     taken to be 7.5 in/yr. Lake areas from DNR model.

         My own review of DNR's model (letter to N. A. Ostenso of March 10)
     indicates that the DNR impact seepages could be as much as 60% low.

         Clearly the four lakes in question are not perched or isolated from
the
,.ground water. Yet despite the relabelling, they are still being treated
as
(274)such. This issue will become much more important in the final two chapters
of
x    the DEIS where pumping's impact on these lakes and the mitigation plan
for
     that impact are covered.



-8-



--l-               , , ,. , ,. I                      .. I              
 -



Co9_