ML19347D234
| ML19347D234 | |
| Person / Time | |
|---|---|
| Site: | Bailly |
| Issue date: | 02/18/1981 |
| From: | Frederick D INTERIOR, DEPT. OF, GEOLOGICAL SURVEY |
| To: | Shorb E NORTHERN INDIANA PUBLIC SERVICE CO. |
| References | |
| EGS-233427, NUDOCS 8103110520 | |
| Download: ML19347D234 (36) | |
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Chairman, Nuclear Regulatory Comission 4
{ ) United States Department of the Interior
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The Interier Pe::artment ha: asked that the Ceelegical Survry resprnd to the criticise: of it: wcrk centaired in ycur letters of .Nove-ber ,10c.0. and teestber 9,1~00, to Secretarj of the Ir.t*: rice !.ndrus, and in t5c c'ecimnt:
accc ;anyin: the:e letters. Your lettee of 'JeverM- 3,1~??. was acco-'anied 5y a crey of ycur letter te "r. t: reld Certer, rirceter of "uclear 'incter r e:ulatin . "ucb>2r r etulatory Co--ission ("~i), and a cery of the a:tsch ent te that letter. De attack .ent su--arizac tSe cejor ;+ia: rate in 2 rere-t
. ty O'f ppolenia Consultir , En;ireerc c: titlW ".'3:ess~2ct of the bfluence ef T-ewatering at Bailly '!-1." That report, sich e-bcdict extensive criticis:-
l cf two D.9. eclocical Furver D.'S'.O rape-:: cc -round -at-r cersitient at l
ttc ! . diana ru-=c ' atirnal Lakesbern, ms in torn fc:-*::rdtd in its catir:'ty I
at an eccleci:re to you- letter ef Tere-her e, IC. T'e t'o er nett in
! cu:: tion are 'J.*:. Cecle-ical Survev
- ster Sesa" recs Irvr:tica:icrs Ocrert 75-12R and L'i. ccolce:ical Survey 0;cn-rile ecport 3^-110',.
All uacertairty cannot be re evei frrm a crcunf-vater analysis. The
~1ecic;ical Turvey re:orte reccenize thic and centain extensive definitten c+
l the -athodole;ical licitatices f our studics. "a'y of tSe criticis-s effered in the D'*;pelenis rercet are si cly reestittens cf t%rc limit?tions, a d of course, ye hr.ve oc rc2:en te disagree with these ::ccific criticis*s.
- art from this, however, t*e C't.crolonia analysis introduces nu.ercus criti-cis : whicr. we bel.ieve te he incorrsct and. unfcunded. These are cdcressed in t7e ace n tnying eacle: urns.
Enclesure 1 offers re e crecific cem2ntr rcmrdinC reints raised in ycur i
letter of Pece-J:er P. lee 0, :: 7ecretary of t:e Interior encrus. E.clcsure 2 was prepared as a resrense to the "eints raised in the enciesure tc ycur letter to Mr. Dente :. Ccpies cf enc!csure: 1 and 2 are aise beine forsarded r
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- 2 to the NP.C and the !!ational Park Service. Geological Survey cersennel feel that the major criticisms in the D'/.ppolenia analysis are ansi ad in the two enclosures, and no furthtr content on the D' Appolonia reper, will be offered at this time.
If you have any cuestions regarding the enclosed material, please iet us know.
Sincerely yours, IC]IlI.IfdRIf Dcyle O. Frederick Acting Directer Enclosures Copies to:\ Chairman, Vuclear Reculatory Cennission Director, ? ational Park Service l
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r ENCLOSURE 1 Follcwing is the U.S. Geclegical Survey (USGS) res;0nse to ;0ints raised in the letter frem Mr. E. M. Sherb, First Vice President, Ner hern Indiana Public Service Cc=pany (NI?SCO), te the Secretary of the Interice, dated December.3, 1950.
On page 2 there is a discussion of the questien of whether the i= pacts cf dewatering were adequately addressed in the criginal Environmental I:;act Statement (EIS). 7his question dces not refer to naterial in the USGS re;crts, but rather to a statement in Secretary of the Interior Andrus' letter of December 3, 1980. For the' recced, hewever, it shculd be noted that when the original EIS was prepared, the dewatering plan involved only pu=page frem the uppermost sand unit. The analysis did not censider the effects of pu=page from the icwer sand. In 1979, NIPSCO prepesed a revisec dewatering plan involving pumpage from both the upper and icwer sand units. Thus, bewever adequately the earlier analysis addressed the effe:ts of dewatering according to the criginal plan, it certainly did not address the effects of dewatering according to the current plan. The only ' place that these effects have been addressed to any degree is in the work su=marized in USGS Open-File Reper:
80-1105. .
On page 2 there is also a statement that ". . . the continuous monit: ring of grcund-water levels preves conclusively that drawd:wn effects have been confined to NIPSCO property." Figure 7 of USGS Open-File Report 30-1105 shows water-level changes as redicted by the USGS : cel for a ;cin: on the NI?SCO-NPS bcundary, as a result of pumpage at the rates er;Icyed to date.
The predicted drawdewn is approximately 0.3 feet. A change Of this magnitude is ncrmally difficult to isolate from seasonal fluctuati:ns and ::her influences-in a field hyde: graph. The significan: point is : hat the :: del prediction of very little drawdcwn cu: side the NIFSCO area due :: the presen:
.;u= age is in agreement with field cbservations, within the targins cf errer in these cbservations. It is also significant that the USGS =cdel is atle to reproduce current dewatering effects within the NI?SCO area, where drawdewns l
i are greater and can be measured with =cre ecnficence.
On page 3, reference is made to a ;umsing test whi:n indicates a icw value of
) per=eability in the NIPSCO area. As indicated in enciesure 2, the USGS j disagrees witn the ic.<er permeability figures which have been pretcsed. Atten-l tion is directed in particular to the fact that the USGS has tried Icwer j values of permeability in its model and has attempted to match the effects of the dewa:ering pumpage to date using these figures. The match ce: ween =cdel results and observed field data using the lower permeability is markedly inferior to that cbtained with the higher permeability derived by USGS persennel.
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4 The Geological Survey disagrees with the assertion on page 3, referring to USGS predictions of water-level changes in the Cowles Scg area, that ". . . no technical substantiation for the prediction was offered." NIPSCO was advised, at the meeting in cuestion, that the predictions were made using the USGS three-dimensional ficw model. This model is fully described in USGS Water-Resources Investigations Report 78-138, which had been released approximately 1 year prior to the subject meeting. In the view of the USGS, this report provides thorough technical substantiation for the predictions.
At the bottom of page 3, referring to a connection between the lower and upper sand units in the Cowles Bog area, it is stated that ". . . the USGS report concedes that there is virtually no evidence of such a connection in the bog area." Had no evidence been present, the USGS would not have incorporated the connection in its simulation. The evidence consists primarily in the relative success of model calibration for the two conditions. Simulations incorporating the enhanced ccnnection between the two units prcduce water levels in the upper sand which agree more closely with field data than do simulations which do not incorporate the connection. Further evidence, not mentioned in the report, was derived from tritium isetcpe analyses. The tritium centent of ground water frcm the upper unit in the Cowles Sog area is low, matching that of water from the lower sand unit elsewhere in the National Lakeshore. In contrast, the tritium content of water frca the' upper sand unit elsewhere in the Lakeshore has been found to be relatively high, as is ncrmally the case for shalicw ground waters. This indicates that the water in the up;er unit at Ccwles Bog is derived primarily frcm the lower sand unit, through upward discharge, which in turn im: lies vertical interconnectien--that is, a relatively high permeability of the material between the two units. Of course, the USGS agrees that the evidence fer interconnection is indirect. It is custcmary in ground-water analyses to consider all available evidence. direct and indirect, in order to develcp a.ccherent representation of the ficw system.
i The qualifying statements in USGS Ocen-File Report 80-1105 wnien are quoted j cn pages 4 and 5 of your letter reflect the way in which the USGS views the l current status of cur knowledge of the hydrology of the Lakeshcre area.
This does not change the fact that the USGS analysis is the most comprehensive that has been made to date and, therefore, offers the best available informa-tion on the probable impacts of dewatering.
With regard to mitigation schemes, the comments in Report 80-1105 refer only to-the two schemes proposed by NIPSCO and tested by USGS in its analyses.
It was not the Geological Survey's intention to imply that mitigation is i generally impossible.
l The criticisms of the USGS analysis in the icwer part of page 5 are answered l in enclosure 2. For the record, the USGS disagrees with the centention that
! an analysis which employs state-of-the-art techniques such as three-dimensicnal l
simulation should not be accepted as ". . . an engineering analysis upon which reliable conclusions can be based." whereas an analysis which relies upon i empirical estimates, involving arbitrarily assumed parameters, can be accepted in this sense.
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i ENCLOSURE 2 Following is the U.S. Geological Survey's (USGS) reply to the points raised in the enclosure sent to the Ofrector of Nuclear Reactor Regulation, Nuclear Regulatory Commission (NRC), by E. M. Shorb, First Vice President, Northern Indfana Public Service Company (NIPSCO), concerning USGS Reports No.78-138 and No. 80-1105. For clarity, the comments made in the enclosure to Mr. Shorb's October 21, 1980, letter to NRC are quoted, then the USGS response is presented.
Quote from enclosure to Mr. Shorb's letter:
I. A preliminary review has been made by D'Appolonia Consulting Engineers with respect to the soil parameters used in USGS Report No.78-138 (Ref.1). The results of that review are set out in Ref. 3 and can be summarized as follows:
- 1. A large body of field data relative to soil parameters within the study area has been collected over a 20-year period; the USGS reports do not reflect much of this data. -
USGS response:
i To our knowledge, no data were neglected in preparing the USGS reports. The enclosure to Mr. Shorb's letter does not specify what data the USGS failed to j consider; however, the data base of tne two USGS reports includes a large amount of information obtained from Bethlehem Steel Company (BSCO) and NIPSCO, through requests under section 30S(a) of the Federal Water Pollution Control l Act, in addition to data frem 30 new wells constructed by USGS. The source of data used by the D'Appolonia report presumably is the same as that used by the USGS reports; however, the USGS is requesting the data used in the D'Appolonia l report through NIPSCO for further study. Much of the well boring data mentioned l in the D'Appolonia report apparently are.within the building area of SSCO and
'are thus limited to a localized point--in contrast to the data collected by USGS for the entire Lakeshore. In summary, the USGS did consider the data filed in l BSCO, NIPSCO, and other agencies. Until NIPSCO specifies all of the data used in the D'Appolonia report, it is impossible for USGS to evaluate the validity of the criticism that the USGS recorts do not reflect soil-parameter data collected over the past 20 years.
Quote from enclosure to Mr. Shorb's letter:
- 2. Thtre are significant discrepancies between the actual field data and the data or assumptions used by the USGS.
USGS response:
The information on which the USGS reports are based includes all the USGS field data, and all other field data of which the USGS was aware, or which its personnel could acquire. As in any hydrologic investigation, these field data
'had to be processed and interpreted before they could be used in analysis.
.Again as in any investigation, assumptions had to be made regarding those aspects of the problem for which no data were available. However, the USGS is unaware of any discrepancies between actual field observations and the set of data which was analyzed in developing the two recorts.
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Quote from enclosure to Mr. Sherb's letter:
For example: .
- a. The wrong per=eabilities were used for Units 1 and 3 (upper and lower aquifers).
i USGS response:
The D' Appolonia report quotes two methods of permeability determination.:
analysis of pumping tests, and estimation from the grain-size distribution using an empirical formula. Pumping test analysis provides a value of transmissivity, or permeability multiplied by thickness of flow; permeability is calculated by dividing the calculated transmissivity by the assumed vertical thickness of the flow pattern. It is the USGS's understanding that, for the two pumping tests in question, .the maximum feasible thickness of flow was assumed, so that calculated permeabilities turned out to be correspondingly low.
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In the studies reported in USGS Water-Rescurces Investigations Report 78-138, an initial estimate of permeability was made through an analysis of specific capacity data frem four wells in the western section of the study area. The technique of analysis was similar to that normally employed in the anal' y sis of pumping test data for nonequilibrium conditions, and again led initially to a value of transmissivity. This transmissivity was divided by the vertical thickness of the flow pattern, which was assumed equal to the length of screen in the well, to obtain a permeability figure. The average of the permesbility figures obtained in this way was 157 ft/ day; this was taken as an initial value of permeability for purposes of model analysis. It can be argued that the
- thickness of flow could be greater than the screened interval, although USCS experience with specific capacity analysis indicates that this is not the usual case. Close to the discharging well--that is, in the region sampled in a specific capacity test--the flow pattern tends to be horizontal and largely confined to the screened interval. Thus, for estimating permeability from specific caoacity results, the screened length is usually the best estimate of flow thickness.
l In any case, however, it shculd be noted that the specific capacity analysis was used caly to obtain an initial estimate cf permeability. Had the model L.
developed with this permeability not been able to reproduce conditions observed prior to and during the dewatering that has occurred to date, the permeability figure would have been revised. In point of fact, however, agreement between L model results and field observations, both for pre-dewatering conditions and for the present dewatering operation, has been very good. In contrast, when
! lower permeabilities were used in the model, the agreement between model results and field observations was less satisfactory.
Subsecuent to the publicatica of Water-Resources Investigations Report 78-138, specific capacity data were assembled for 40 wells throughout the Lakeshore
- area and were analyzed to determine permeability. The average permeability obtained from these 40 analyses was 150 ft/ day, which is close to the value of 167 ft/ day used in the. simulation.
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The permeability estimates made frem grain-size data in the D'Appolonia analysis employed an empirical equation proposed by Hazen. Tertaghi, in describing this method, suggests values of the coefficient C ranging frem 100 to i30 for uniform sands. A value of 100 was used in the D'Appolonia analysis, leading to permeabilities ranging frem .01 cm/sec to .04 cm/sec. Had a value of 150 been used, the range would have been from .015 cm/see to .06 cm/sec' The permeability of 167 ft/ day used by the USGS is equivalent to approximately .0589 cm/sec.
Thus, the method could easily have been used to support the USGS permeability, depending on the choice of C; and, in any case, there is widespread agreement that the empirical approach is very approximate and should be used only where local experience has provided some insight into the possible range in the coefficient C. .
In summary, the USGS feels that the permeability of 167 ft/ day is a good approximation to field conditions in the Lakeshore area and that the permeability proposed in the D'Appolonia report is unrealistically low.
Quote from enclosure to Mr. Shorb's letter:
- b. At many locations, the wrong surface elevations of Unit 2 were used in USGS reports.
USGS response:
After reviewing USGS Report No.78-138, the USGS agrees that there is an error in contouring the top elevation of Unit 2 at one locaticn; bewever, although this error appeared in the report, it was'not incorporated in the model input and thus did not affect the simulation results.
Quote from enclosure to Mr. Sherb's letter:
- c. Unit 3 is connected to the sands above Unit 2 through many large openings and it is also connected to Lake Michigan. Unit 2 is not continuous as USGS assumed.
USGS response:
No place in the USGS reports is it stated that USGS assumes Unit 2 is continuous.
On the contrary, the reports state clearly that there are discontinuities in Unit 2. USGS Report No. 60-1105 indicates that there may be a discontinuity in Unit 2 under Cowles Bog.
Quote frem enclosure to Mr. Sharb's letter:
- d. Units 1, 2 and 3 are different in shape and in thickness frem those used in the model.
USGS response:
The D'Appolonia. report failed to include the data used to estimate the thickness of Units 1, 2, and 3; therefore, it is impossible to evaluate whether or not the 3
I D'Appolonia's estimation of formation thickness is correct. However, the USGS subsequently has used the thickness maps presented in the D'Appolonia report as.model input to evaluate the impact of D'Appolonia's interpretations on model simulations. Except for minor deviations in water levels, no significant deviation from the results presented in USGS reports has been observed.
. Quote from enclosure to Mr. Shorb's letter:
- e. There are major differences between actual ground water levels and those assumed by USGS.
USGS response:
The error in contouring the top elevation of Unit 2 at one location presented in the USGS Report No.78-138 was the reason for this statement. The D'Appolonia report used the top elevation of Unit 2 and'added the saturated thickness of Unit 1 to obtain the ground-water level at the area where the contouring error occurred and compared this. calculated.value with the observed water level.
Except for the one area where the USGS report contained the contouring error, the D'Appolonia report failed to indicate any difference between the model simu-lated water levels and the measured water levels. The use of plural in the statement distorts the fact. On the contrary, if the D' Appolonia repor,t compared the water levels observed on October 26, 1976, with the model simulated water levels (USGS Report No.78-138, figure 25), the simulated water level is well correlated with the observed water level.
Qucte frem enclosure to Mr. Shorb's letter:
- f. Two different aquifers (unconfined and conficec) do not exist throughout the study area as assumed by the USGS; in many areas they are connected and act as one.
USGS response:
This is a rewording of item 2c. USGS reports state clearly that there are dis-continuities in Unit 2. When Unit 2 is missing, Unit I and Unit 3 are naturally connected and act as a single aquifer. The model presentad in the USGS reports simulated this condition accordingly.
Quote from enclosure to Mr. Shorb's letter:
- 3. The radius of influence for the pressure relief system was calculated using actual permeabilities and pump test results and found to be less than 950 feet. Therefore, the system cannot have any effect on Cowles Bog which is located over 8,000 feet from the Bailly Nuclear-l site.
USGS response:
The method used by D'Appolonia to estimate the radius of influence was developed as an empirical formula by Sichardt in 1930. It was customary at that time for engineers to estimate the pumpage required to dewater an excavation using the 4 .
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Thiem ecuatien, in which one cf the required parameters was the " radius of influence" R. Sichardt's method was intended to supply a rough estimate of R for use in such calculations.
!.iterally, the radius R required in the Thiem equation is the intercept, on the zero-drawdown axis, of the linear pcrtien of a plot cf drawdown vs. distance on semilogarithmic coordinates. It is not the point at which drawdewn is :ero, except in those rare cases where the distance-drawdcwn plot is en;tirely linear throughout its radial extent. A cursory review of the literatura of nonequilibrium ground-water flow, er of steady-state flew where vertical mcvement is involved, will show that in general the distance-drawdown plot consists of an inner linear segment and an extensive nonlinear portion. The actual radius at which drawcown is found to be zero is ner= ally several times further frem the pump,ing center than the intercept, R, of the linear per:f on of the graph.
Sichardt's method provides an acceptable estimate of the intercept radius, R, for pur;cses of pu=page calculation using the Thiem equatien, provided a suitable estimate fer the parameter C is found. The statement :nat there is no drawdown beyond this radius involves the assumption that a samilogarithmic distance-drawdown plo extending away frem the excavation would be entirely linear.
This contradicts hydraulic theery, general hydrologic experience, and the results cf the USGS simulations. -
Qucte frem encicsure to Mr. Sherb's letter:
- a. The radius cf influence frem the pressure relief system will not reach the beg area even if it is assumed that Unit 2 is continucus thrcughcut the study area with an opening ("windew") enly under :he beg.
USGS res::ense:
The response to item 3 also applies to thi's statement.
Cucte frem enclosure to Mr. Shore's letter:
, 5. Fcr these reasens it is concluded tha: the model, as presently constructed, does not suc;cr: any conclusien that the pressure relief system will affect the Ccwles Bog area.
USGS response:
The USGS asserts that its two reports are valid. The arguments raised in the D'Accolcnia reper de not contain sufficient and convincing reascns Oc revise tne twc' USGS recorts. On the contrary, the mcdel simulated water levels are well ccrrelated with water levels observed in Oct ber 1975 (USGS Recer: Mc.75-139, figure 25). Further, the simulated water-level declines in and near the excavatten site during phase-1 cewa aring are also well ccrrela ad wi-h 5
the water-level declines observed in August 1978 and September 1979 (US S Report No. 80-1105, Table 1). This demonstrates the reliability of the model presented in the USGS reports.
Quote from enclosure to Mr. Shorb's letter:
II. The recent USGS Report No. 80-1105 (Ref. 2) is currently being reviewed. Significant discrepancies discovered thus far are as follows:
- 1. The storage properties of the marsh (wetland) surrounding Cowles Bog are not included in the computer model developed by USGS. The wetland west of Mineral Springs Road and surrounding the 10-acre, elevated portion of Cowles Bog consists of over 200 acres. Even if it is assumed that USGS model predictions are correct, construction dewatering will not cause groundwater changes in the Cowles Bog area as the 200 acres of wetlands will offset any groundwater decline.
USGS response:
Report 80-1105 states, page 2, that the storage properties of the marsh were not included in the model but could'be incorporated in an expanded model to refine the estimates of the impact of pumpage. Inasmuch as this has not been done to date by the USGS or D' Appolonia, the USGS believes the assertion that ". ..
construction dewatering will not cause ground-water changes in the Cowles Bog area as the 200 acres of wetlands will offset any ground-water declines." to be speculative and unsupported by facts or analysis at .is time.
Quote from enclosure to Mr. Shorb's letter:
- 2. The following statement appears at page 3 of Ref. 2:
"The USGS and the NPS have collected new hydrologic data in the vicinity of Cowles Bog. These data suggest that (1) the confining unit (Unit 2), normally present between the unconfined aquifer (Unit 1) and the confined aquifer (Unit 3), may be thin or absent; (2) the vertical hydraulic conductivity of Unit 2 may be greater than it is elsewhere; or (3) a combination of items (1) and (2) may exist in the area of the bog. This " discontinuity" in tne confining unit would greatly enhance the hydraulic connection between the unconfined and confined aquifers and could iiltensify the impact of construction dewatering on water levels at Cowles Bog, particularly if; a large part of the water pumped from the excavation came from Unit 3." ' Emphasis added) 6
That statement is qualified to such a degree that the Secretary cannot appropriately characterize it as concluding that de-watering at Bailly Nuclear-1 ". . . will result in water level declines at Cowles Bog . . ." (Emphasis addea).
USGS response:
Because no boring was made at Cowles Bog, there is no direct evidence to indicate that Unit 2 is missing beneath the bog. However, better agreement between field data and simulation results is obtained when the simulation incorporates an enhanced hydraulic connectic.7 between the two units at Cowles Bog. Further evidence is provided by tritium concentrations in the ground water near Cowles Bog. The tritium contelt of ground water from the upper unit in the Cowles t Bog area is low, matching that of water fran the lower sand unit elsewhere in the National Lakeshure. In contrast, the tritium content of water from the upper sand unit elsewhcre in the Lakeshore has been found to be relatively high, as is normally the case for shallow ground waters. This indicates that the water in the upper unit at Cowles Bog is derived primarily from the lower sand unit through upward leakage. It is actually immaterial whether the upward movement of water from Unit 3 to Unit 1 is due to the total absence of confining material or due to an increase in the vertical permeability of the confining unit. The model used a large value of the vertical permeaoility of Unft 2 at Cowles Bog to simulate the system; whether this reflects the absence of Unit 2 or an incr1ase of the vertical permeability of Unit 2, the results are the same. The high degree of qualification in.the quoted statement is merely a prudent way of distinguishing a conclusion based on technical inference from a statement of fact based on direct evidence. .
Quote frem enclosure to Mr. Sharb's letter:
- 3. Data from Ref. 2 shows that the average groundwater level in the 1.ower aquifer (Unit 3) was at Elevation 589.8 ,
l (Nov. 7, 1979) inside the excavation for Nuclear-1. The USGS performed a model simulation to reduce the hydro-static pressure to Elevation 583.7 (pages 10 and 15), a reduction of 6.1 feet. For this small reduction at the excavation, the model predicted groundwater declines in the bog area over 8,000 feet away. This predicted reduction of the groundwater level in the Cowles Bog area is contrary to pumping tests and observed data at the NIPSCO and BSCO sites and to empirical data presented in engineering literature. (SeeRef.5). In effect, the USGS by making incorrect modeling assumptions, arrives at a conclusion that violates fundamental hydraulic principles and is contrary to observations of the effects of dewatering at and near the sites of Bailly Nuclear-1.
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USGS response:
Fundamental hydraulic principles have not been violated by USGS. The USGS and most hydrologists believe that " state-of-the-art" modeling should give better and more accurate results than those arrived at by empirical equations.
The simulated water-level declines due to dewatering in and near the excavation sites are wel.1 correlated with the water-level declines observed in August 1978 and September 1979 (USGS Report No. 80-1105, Table 1). This fact indicates that the USGS conclusions are valid.
Quote from enclosure to Mr. Shorb's letter:
- 4. The following statement appears at page 27 of Ref. 2:
"Whether the actual ground-water system will behave in the same manner as the model simulation depends on how well the model simulates the physical properties of the ground-water system and the artificial recharge of water for mitigation. Therefore, these model simulations should not be viewed as precise predictions of what will occur in the field, but rather as an estimation of what may occur." (Emphasis added) -
In other words, the results of any model will cnly be as good as the data and/or assumptions incorporated in the model. Since, as we have shown in Ref. 3, the USGS model does not simulate actual physical properties of the ground-water system in the study area, the model cannot reliably
, predict groundwater movements in Cowles Sog. The USGS j' Report therefore does not provide valid support for any i
conclusion that its estimates of what "may occur" are accurate.
USGS response:
l As discussed before, the USGS disagrees with the statement presented in the D'Appolonia report that the USGS model does not simulate actual physical properties of the ground-water system in the study area. The high correlation 6
between the simulated and observed water levels and the simulated water-level declines in a time span of 3 years (1976-1979) and under different stress conditions (natural versus dewatering) strongly suggests that the USGS model accurately simulates the actual physical properties of the ground-water system in the study area.
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-Quote from enclosure to Mr. Shorb's letter:
- 5. The conclusion of Reference 2 states:
"Because the flow model has not been verified, it can only be used in a general way to evaluate che effect of construction dewatering and decline of the seepage mound on ground-water levels in and near the Lakeshore. Until the model-simulated estimates of water-level decline can be compared with measured declines, the accuracy of the simulated declines cannot be determined."
We would emphasize that this passage admits: the flow model has not been verified speculative. and conclusions drawn from its use are therefore In fact, the actual field data shows that the model is not valid.
USGS response:
The statement, "In fact, the actual field data shows that the model is not valid."
is incorrect and distorts the fact. The model simulated water levels are well correlated figure 25).withUsing water levels observed in October 1976 (USGS Report No. '78-138, the same model, the simulated water-level declines in and L
near the excavation site are also well correlated with the water-level declines abserved in August 1978 and September 1979 (USGS Report No. 80-1105, Table 1).
These good correlations from a 3-year interval under different stress conditions
! indicate the capability of the model. However, the USGS would caution that the degree of accuracy of the model simulated water-level declines cannot be deter-l I
mined until the model is fully verified by long-term field data. This conclusion l implies that there would be scme differences between the observed and simulated water levels. The conclusion of Report No. 80-1105 is that the model can be
! used for evalu: tion of the impacts on the ground-water system in the study area t
i caused by construction dewatering and decline of the seepage mound; however, the magnitudes of water-level decline cannot be simulated exactly. As with any prediction, there is an element of uncertainty associated with the predictions derived frem the model analyses. The USGS reports acknowledge that fact and call attention to the limitations of the model and the need for additional hydrologic data to refine the model design. The USGS believes, however, that the use of a simulation is the most powerful means available for developing predictions of water-level change.
References:
Ter:aghi, Karl, and Peck, R. B., 1948, Soil Mechanics in Engineering Practice:
John Wiley & Sons, Inc. , ihn< York, p. 44..
Sichardt, W., and Kyrieleis, W., 1930: Grundwasserabsenkungen bei Fundierungsarbeiten, Berlin.
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DEPARTMENT OF THE INTERIOR NATIONAL PARK SERVICE -
ASSOCIATE DIRECTOR, SCIENCE & TECHNOLOGY rigt- ,
W ' =~ 16,1980 g' ~.,f f T Ira:
5 .l This letter frcm hTiSC3 deals in large part with AI,k jr highly technical data relatirs to the 41.rclogy of .y ,7i' g the Cowles Ecg area.... spa mm11y with USGS studies carried cut for the Park Service conce=17p.= ping d %. 1 effects en the Ccwles Scg water table level.
Therefore, the USGS shx.1d prepare the draft resxnse-to this let's .
NPS will review the CSGS draft raterial and add b appewtiate langr. age covering the policy ratters raised in the NIPSCO let's .
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CHIEF HYDROLOGIST O
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....r wec.....oc , December 8, 1980 l
Mr. Cecil D. Andrus Secretary U.S. Department of the Interior .
Office of the Secretary Washington, D.C. 20240
Dear Secretary Andrus:
I wrote on November 3, 1980, advising you that the conclusions ~
stated in your letter of October 3, 1980, to Chairman Ahearna of the U.S. Nuclear Regulatory Corrtissicn are of questionab.te validity. -
I also stated that Northern Indiana Public Service Company (NIPSCO) t would soon submit a detailed response to,your letter and the U.S.
Geological Survey reports upon which it was based. That detailed _
report, " Assessment of the Influence of 6ewatering at Bailly N-1" prepared for NIPSCO by D'Appolonia Consulting Engineers, Inc.,
is enclosed.
~
In large part, the report speaks for itself'and I shall not attempt to state or restate every point =ade therein. How-ever, I deem it essential to emphasi::e the principal conclusions to be drawn from the report, draw your attention to some of the l discrepancies between your letter of October 3 and the reports l upon which it relied, and request that you take immediate steps to halt the activity you set in motion by that letter.
i l
Construction of Bailly Generating Station, Nuclear-1, neces-sarily involves removal of water from the excavation while construc-tion proceeds. As your letter acknowledges, the question of whether dewatering will produce effects (i.e., drawdown of ground-water levels) beyond NIPSCO's property and w.ithin the Indiana Dunes National Lakeshore was considered by NRC's predecessor agency before the construction permit for Bailly N-1 was issued. Your letter states thc.t the prior environmental review " presumed" that the environmental effects of dewatering would be minimal.
Chis statement is inaccurate. Nothing was " presumed;" on the contrary, the best evidence then available was presented under oath, tested by cross-examination, evaluated by a three-person A
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Mr. Cecil D. Andrus Page 2 Dece=ber 8, 1980 Licensing Board of technical and legal experts, ppviewed by an agency appeal board, and appealed to the courts._
Your letter goes on to state:
Subsequent continuous and extensive studies and monitoring have been undertaken both by the applicant [NIPSCO] and by the Department of the Interior (National Park Service and the U.S. Geological Survey). The results of l
this work now lead to the conclusion that the impacts of construction dewatering were inadequately addressed in the original environ-mental statement.
i Literally, that states that some unspecified " work" by NIPSCO l supports the conclusien that "the impacts of constructica ce-watering were inadequately addressed . . . ." That is untrue.
. The results of all studying and monitoring performed by NIPSCO l
confirm the concAusion that the i= pacts of dewatering were properly and adequately addressed earlier. The information collected by NIPSCO over the 6-1/2 years since the construction permit was issued cannot be adequately sum =arized here but I do want you to know the following:
- 1) Dewatering has been conducted continuously since March of 1977 (admittedly, on a scale less than the maximum which will occur); the continuous monitoring of groundwater levels proves conclusively that draw-down effects have been confined to NIPSCO property.
~
- / I do not wish to dwell on minor matters but you-should know l
that the " Final Environmental Statement" (FES) prepared for Bailly N-1 does not represent the only consideration or the last word concerning Federal review of dewatering effects at the construction permit stage. Extensive evidence on fewatering, its effects and mitigation was presented in a contested, adjudicatory proceeding before an Atomic Safety and Licensing Board which concluded that significant adverse L environmental impact to the'Lakeshore would be prevented.
l (7 AEC 589-91.) Under AEC ~(and NRC) regulations the FES is deemed to have been modified by the Licensing Board's decision. (See 10 C.F.R. S '51. 52 (b) (3 ) (1980).)
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Mr. Cecil D. Andrus Page 3 December 8, 1980
- 2) Results of a pumping test at the Bailly site in April of 1979 demonstrate that NIPSCO's expert witness in the construction permit hearing had assumed conservative soil permeabilities when he predicted drawdown effects--
i.e._, that his assumptions are likely to over-predict drawdown.
Therefore, your conclusion must rest upon " studies and moni-toring" by the Department of the Interior. You cite only " Reassess-ment of the Effects of Construction Dewatering on Ground-Water Levels in the Cowles Unit, Indiana Dunes National Lakeshore, Indiana, Supplement to Geological Survey Water-Resources Investiga-tions78-138" (USGS Report 80-1105), a report which in turn relies upon " Effects of Seepage.frcm Fly-Ash Settling Ponds and Construction Dewatering on Ground-Water Levels in the Cowles Unit, Indiana Dunes National Lakeshore, Indiana" (USGS Report 78-138). As the enclosed report demonstrates and we shall summarize below, those reports cannot suffice as the bases for concluding that the impacts of construction dewatering were inadequately addressed earlier.
Your letter states that the Deputy Director of the National l Park Service advised NIPSCO early in 1980:
. . . that proposals for an alteration in the dewatering procedure, together with new in-formation about the hydrology of the . . .
Lakeshore, indicated that construction dewater-
. ing would adversely impact the lakeshore. -
(Page 1, emphasis added.)
That is incorrect. At the meeting to which you refer, NIPSCO was advised that the USGS, using a hypothetical case in its ground-l water =cdel, predicted water level changes up to 0.5 feet in the Cowles Bog area. No technical' substantiation for the prediction was offered. -
I turn now to your. discussion of USGS Report No. 80-1105.
Your letter states that there is strong evidence of a hydrological. connection between the lower aquifer . . . and the surface aquifer . . . at both the Bailly excavation site
' and the central area of Ccwles Bog . . . .
In fact, the USGS report concedes that there is virtually no evidence of such a connection in the bcq reea. The existeEEe of I
7 __ u .. Speasemate N h e O ersegneaev - ,
s.
Mr. Cecil D. Andrus Page 4 December 8, 1980 the connection or " discontinuity" is only a hypothesis for which there is no direct evidence. The USGS and NPS did collect informa-tion indicating that there is a " ground-water =ound" in the Ccwles Bog area. The USGS report then speculated:
The mound is probably produced by the upward dis-charge of ground water from unit 3 into 1 through l a " discontinuity" in the confining unit that normally separates the two aquifers.
(USGS Report No. 80-1105, p. 48, a=phasis added.)
Although the hypothesis of the " discontinuity" in the confining unit at cowles Bog has not been proven with direct evidenes such as test =orings and corings, tne =cund in unit 1 indirectly supports it. The USGS and NPS will continue to gaener data that will expand and refine the present understanding of the hydrology of Ccwles Bog. For now, the hypothesis that a .
" discontinuity" exists in une confining unit under-lying Ccwles Bog is assumed, and the =edel simulations that follow incorporate tnis " discontinuity."
(USGS Report No. 80-1105, p. 32, e=phasis added.)
Your letter goes on to state that the USGS report " indicates tha: . . . construction dewatering will result in watar level declines at Ccwles Bog . . . ." Again, this is an overstatement of :ne results set out in the report. That dccu=ent states that the hypothetical " discontinuity" I
could intensify the impact of constructicn de-watering on water levels at Cowles Sog, particu-larly if a large part of the water pumped frc=
the excavation came from unit 3.
(Report No. 80-1105, p. 3, e=phasis added.)
It must also be recalled that we are talking about predicticas made by a computer simulation:
Simulations also indicate that the " discontinuity" could cause intensified water-level declines in
- unit 1 at Ccwles Bog during phase 2 construction eo .8b-11b5,p.48,emphasisadded.)
Computer simulations can be extremely valuable, of course. Ecwever, as the USGS Report expressly recognizes l
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6 Mr. Cecil D. Andrus. Page 5 Decerbar 8,1980
. . . Whether the actual grcand-water system will behave in the same manner as the model simulation depends on how well the model simulates the physical properties of. the ground-water system and the artificial i recharge of water fom mitigation. Therefore, these model simulations should not be viewed as precise predictions of what will occur in the field, but rather as an estimation of what may occur . . . .
(Report No. 80-1105, p. 27, emphasis added.)
It is therefore incorrect to characterize, as your letter does, the report as concluding "that those [ estimated) water level l declines cannot be fully mitigated."
The conclusions stated in the USGS report are expressly
! qualified to an extraordinary degree. The report therefore cannot be accepted as an engineering analysis upon which reliable conclusions can be based. In fact, the observed data does not support the hypothesis incorporated in the report.
I on the contrary, we submit that the hard evidence, including field data, presented in the enclosed report supports these conclusions:
l
- 1. Using actual field data (including the results of pumping tests and demonstrated perneabilities), the calculated lateral extent of drawdown produced by NIPSCO's planned dewatering system (the " radius of influence") is less I
than 950 feet. Even when the erroneous coefficient of permeabilities assumed by the USGS is used in the calcu-lations, the radius of influence does not exceed 1450 feet. It is therefore clear that dewatering associated with construction of Bailly N-1 cannot have any effecu l on Cowles Bog, which is more than 8000 feet away.
- 2. The drawdown predicted by the USGS is wrong and unreliable for several reasons. The USGS model ignored or misused a substantial body of field data available for the study
- area. The assumptions used by USGS bear little resem-blance to the field data. Finally, there are defects in application of the model itself.
, The effects of dewatering were carefully and accurately ad-dressed during the Bailly construction permit hearing on environ- ,
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Mr. Cecil D.. Andrus Page 5 Decenber 8, 1980
. . . Whether the actual grcund-watar system will l
behave in the sane manner as the medel si=ulation depends on how well the model simulates the physical properties of the ground-water system and the artificial recharge of water formmitigatien. Therefore, these model simulatiens shculd not be viewed as precise predictions of wnat will occur in the field, but rather as an esti=atien of what may occ"*
(Report No.~80-1105, p. 27, empnasis added.)
l It is therefore incorrect to characterize, as your letter does, the report as concluding "that these- (estimated] water level declines cannet be fully mitigated."
The conclusions stnted in the USGS reper: are expressly qualified to an extracrdinary degree. The repor- therefore
! cannot be accepted as an engineering analysis u;cn which reliable l
conclusions can be based. In fact, the observed data does not support "
she hypothesis incorporated in the report.
l On the contrary, we submit that the hard evidence, including
- field data, presented in the enclosed repcrt suppcrts these l conclusions
l .
- 1. Using actual field data (including the results of pumping tests and demonstrated permeabilities), the calculated lateral extent of drawdewn produced by N:?SCO's planned l dewatering system (the " radius of influence") is less i
than 950 feet. Even when the erroneous ccefficient of l permeabilities assumed by the USGS is used in the calcu-lations, the radius of influence does net exceed 1450 feet. It is therefore clear that dewatering associated
! with:constructaan of Sailly N-1 cannot have any effect j on.Cowles Bog, which is =cre than 8000 feet away.
l 2. The drawdown predicted by the USGS is wrong and unreliable i
- 1. for several reasons. The USGS model ignored or misused l a substantial body of field data available for the study l areae The assumptions used by USGS bear little resem-l blance to the field data. Finally, there are defects in application of the medel itself.
i-The effects of dewatering were carefully and accurately ad-dressed during the sailly construction permit hearing on environ-
we se mm e e -. .
Mr. Cecil D. Andrus Page 7 December 8, 1980 preparation of a supplemental environmental i= pac't statement at this time.
Very truly yours, l
ff 0 l CC' I
EMS /dgg Enclosure cc: R. Dickenson, Director National Park Service J. Whitehouse, Superintendent Indiana Dunes National Lakeshore D. K. Stewart, District Chief l U.S. Department of the Interior Geological Sursay-Water Resources Division i
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Mr. Cecil D. Andrus Page 7 Decerter 8, 1980 preparation of a supplemental environmental i= pact statement at this time.
Very truly yours, ll W lsO -l EMS /dgg Enclosure cc: R. Dickenson, Director National Park Service J. Whitehouse, Superintendent Indiana Dunes National Lakeshore D. K. Stewart, District Chief -
U.S. Department of the Interior Geological Survey-Water Rescurces Divisien T
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OFFICE OF THE SECRETARY
,s WASHINGTON, D.C. 20240 DEC '3 1980 h g&
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CA.g,4Lu-k, Memorandum b
Tc: Director, U. S. Geological Survey -
, , 3 tcB0 Through: Assistant Secretary--Energy and Minerap --7 From: Special Assistant for Minerals p y f
h
Subject:
Reply to Eugene f:. Shorb, Northern Intif ana public SJrvice Company, Concerning Bailly Generating Station Nuclear 1 Mr. Shorb has taken vig,orous issue with the findings of the Geological Survey contained in Open File Report 80-1105 (see attached letter).
The Assistant Sacretary for Energy and Minerals feels that since Survey's work is being challenged, Survey should have the opportunity to reply. The Secretary has promised a respons.c to Mr. Shorb by January 1, ,
so we w.ill need your prepart.J reply in this office by C03 Wednesday, December 17, 1980.
Attachment RECEIVED DEC 9 1980
- CHIEF HYDROLOGIST o
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United States Department of the Interior L >
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OFFICE OF THE SECRETARY WASHINGTO.N*, D.C. 20240
'S 1980
/ wee DEC 4% & g,,gc
. M i dyl M - j DA.s,94k /#s:
7 Memorandum
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To: Director, U. S. Geological Survey Through: Assistant Secretary--Energy and Minera s
~
' / 3 1980 From: Special Assistant for Mincrals y ((f/
Subject:
Reply to Eugene M. Sherb, Northern indiana Public Service Company, Concerning Sailly Generating Station Nuclear 1 Mr. Sharb has taken vig,orous issue with the findings of the Geological Survey contained in Open File Report 80-1105(seeattachedletter).
The Assistant Secr2tary for Energy and Minerals feels that since
' Survey's work is being challenged, Survey should have the opportunity to j reply. The Secretary has promised a response to Mr. Shorb by January 1, , _
i so we w.ill need your prepared reply in this office by COB Wednesday, December 17, 1980.
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Attachment i
f RECEIVED 1
DEC 9 1980 CHIEF HYDR 01.0 GIST l
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i Mr. Cecil D. Andrus Page 2 November 3, 1980 Ssrvice and the Superintendent of the Lakeshore by NIPSCO on September 26, 1980. The D'Appolonia report demonstrates that many of the assumptions upon which USGS reports rest are incorrect.
I am enclosing a coev of a letter which NIPSCO recently sent the NRC's Director of Nuclear Reactor Regulation. The letter and its atta ;ngn$ identify some of the inadequacies of the_two USGS repo s and demonstrate why they can_not ce relied upon in reaching the conclusions stated in your letter. Our letter also explains that we are preparing a detailed response to your letter and the USGS reports. We shall furnish that response to you when it is available. ;
Meanwhile, I note your statement that the National Park Service is convening a " panel of wetlands experts.to addrass the ecological impacts on'the National Lakeshore'of the USGS nodel-simulated water level decline predicted to result from construction dewatering /
. . . ." We urge you to reconsider utilizing the unverified--and, in fact, incorrect--predictions of that model as the basis for any assessment ~ of ecological impacts. We also suggest that any wetlands experts selected for the Park Service panel be persons of outstanding reputation who have not previously taken posi-tions in adjudicatory proceedings or elsewhere regarding the alleged ecological impacts of Bailly construction on the Lakeshore.
Very truly yours, EMS /dgg
( Enclosure
! , cc: W. J. Whalen, Director l National Park Service l J. Whitehouse, Superintendent Indiana Dunes National Lakeshore D. K. Stewart, District Chief l U.S. Department of the Interior l
Geological Survey-Water Resources Division
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i Mr. Cecil D. Andrus Page 2 Nove=ber 3, 1980
. Service and the Superintendent of the Lakeshore by NIPSCO on September 26, 1980. The D'Appolonia report de=enstrates that many of the assumptions upon which USGS reports rest are incorrect.
I am enclosing a copy of a letter,which NIPSCO recently sent J '
the NRC's Director of Nuclear Reactor Regulation. The' letter and l its attachment identify some of the _ inadequacies of the two USGS repotEs and dame =Wate why they cannot me relied upon in reaching the conclusic=s stated in your letter. Our letter also explains that we are preparing a detailed response to your letter and the USGS reports. We shall furnish that response to you when it is available, i
i Meanwhile, I note your statement that the National Park Service
' ~
is convening a " panel of wetlands experts to address the ecological impacts on'the National Lakeshore of the USGS model-simulated -
water level decline predicted to result from construction dewatering /
. . . . We urge you to reconsider utilizing the unverified--and, in fact, incorrect--predictions of that model as the basis for
- any assessment'of ecological impacts. We also suggest that any wetlands experts selected for the Park Service panel be persons of outstanding reputation who have not previously taken posi-tions in adjudicatory proceedings or elsewhere regarding the
- alleged ecological impacts of Bailly construction on the Lakeshore.
Very truly yours, e .
f ,
, EMS /dgg Enclosure
, cc: W. J. Whalen, Director National Park Service J. Whitehouse, Superintendent Indiana Dunes National Lakeshore l D. K. Stewart, District Chief U.S. Department of the Interior Geological Survey-Water Resources Division l
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- Attachmant I. A preliminary review has been made by D'Appolonia Consulting Engineers with respect to the soil parameters used in USGS
. Report No.78-138 (Ref. 1). The results of that re. view are set out in Ref. 3*/ and can be summarized as follows.
- 1. A large body of field data relative to soil parameters within the study area has been collected over a 20-year period; the USGS reports do not reflect much of this data. .
- 2. There are sig'nificant discrepa'ncies between the actual field data and the data or assumptions used by the USGS. .
For example:
- a. The wrong permeabilities were used for Units 1 and 3 (upper and lower' aquifers).
~~
- b. At many locations the wrong surface elevations of Unit 2 were used in USGS' reports.
- c. Unit 3 is connected to the sands above Unit 2 ,
through many large ope'nings and it is also connected 4
to Lake Michigan. Unit 2 is not continuous as USGS assumed.
- d. Units.1, 2 and 3 are different in shape and in thickness from those used in the model.
- e. There are major differences between actual ground .
water levels and those assumed by USGS. ,
~
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- / Copies of.Ref. 3 were provided to the NRC by Mr. Bo,hn's September 26, 1980 letter to Mr. Youngblood.
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I. 'A preliminary review has been made by D'Appolonia consulting Engineers with respect to the soil parameters used in USGS
. Report No.78-138 (Ref. 1). The results of that re. view are set out in Ref. 3*/ and can be summarized as follows:
- 1. A large body of field data relative to soil parameters within ti;e study area has been collected over a 20-year period; the USGS reports do not reflect much of this data. .
- 2. There are sig~nificant discrepa'ncies between the actual field data and the data or assumptions used by the USGS. ,
For example: ,
- a. The wrong permeabilities were used for Units 1 and 3 (upper and lower acuifers).
~
- b. At many locations the wrong surface elevations of .
~
Unit 2 were used in USGS reports.
- c. Unit 3 is connected to the sands above Unit 2 ,
through many large ope'nings and it is also connected to Lake Michigan. Unit 2 is not continuous as USGS assumed.
- d. Units.1, 2 and 3 are different in shape and in thickness from those used in the model.
( e. There are major differences between actual ground water levels and those assumed by USGS. ,
l
- */ Copies of Ref. 3 were provided to the NRC by Mr. Bohn's
- September 26, 1980 letter to Mr. Youngblood. .
l
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assumed that USGS model predictions are correct,
.i. . . ..
construction dewatering will not cause groundwater changes in the Cowles Bog area as the 200 acres of .
wetlands will offset any groundwater decline.
- 2. The following statement appears at page 3 of Ref. 2:
"The USGS and the NPS have collected new- -
hydrologie data in the vicinity of Cowles Bog.
These data suggest that (1) the confining unit
. (Unit 2) , normally present between the uncon-fined aquifer (Unit 1) and the confined aquifar (Unit 3) , may be thin or absent; (2) the vertical hydraulic conductivity of Unit 2 may be greater than it is elsewhere; or (3) a combination of items (1) and (2) may exist in the area of the boc. This
~
" discontinuity" in the confining unit would greatly enhance the hydraulic connection between the ,
unconfined and confined aquifers and could intensify l the impact of constrbetion dewatering on water levels l
l at Cowles Bog, particularly i# a large part of the ,
.w ater pumped from the excavation came from Unit 3."
- (Emphasis added)
That statement is qualified to such a degree that the
.Secretar'y cannot appropriately characterize it as concluding that dewatering at Bailly Nuclear-1 l ,
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. . . will result in water level declines at Cowles Bog . . .
(Emphasis added). -
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'as sum.ed that USGS model predictions are correct, construction dewatering will not cause groundwater i
changes in the Cowles Bog area as the 200 acres of ,
,' wetlands will offset any groundwater decline.
- 2. The following statement appears at page 3 of Ref. 2: -
"The USGS and the NPS have collected new- -
hydrologic data in the vicinity of Cowles Bog.
.These data suggest that (1) the confining unit
. (Unit 2), normally present between the uncon-fined aquifer- (Unit 1) and the confined aquifer J (Unit 3) , may, be thin or absent; (2) the vertical
- hydraulic conductivity of Unit 2 may be greater than it is elsewhere; or (3) a combination of items (1) and (2) may exist in the area of the bog. This
" discontinuity" in the confining unit would greatly enhance the hydraulic connection between the ,
i .
'- unconfined and confined aquifers and could intensify-l .
E . the impact of construction dewatering on water levels I
at Cowles Bog, particularly if, a large part of the ,
1
,water pumped from the excavation came from Unit 3."
. (Emphasis added)
That statement is qualified to such a degree that the Secretary cannot appropriately characterize it as l
l concluding that dewatering at Bailly Nuclear-1 -
i "
. . . will' result in water level declines at Cowles l
Bog . . .
(Emphasis added) . ,
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In othar words, the results of any model will,only be as good as the data and/or assumptions incorporated i
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, in the model. Since, as we have shown in Ref. 3, the USGS model does not simulate actual physical proper, ties of the, groundwater system i'n the study area, the model
- ~
cannot reliably' predict groundwater movements in Cowles Bog. The USGS Report therefore does not provide valid support for any conclusion that its estimates of what "may occur" are accurate. .
- 5. The conclusion of Reference 2 states:
. "Because the flow Etodel has not been ve r ified ,
it can only be used in a general way to evaluate the effect of c6nstruction dewatering
~
and' decline of the seepage mound on ground-water levels in and near the Lakeshore. Until the 1 r model-simulated estimates of water-level decline can be compared with measured declines, the accuracy of the simulated declines cannot be determined." '
We would emphasize that this passage admits: the flow model has not been verified and conclusions drawn from its use are l
therefere speculative. In fact, the actual field data shows that the model: is not valid. s..: J. t . : .
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7 '.'*. . '. : ' , . In othar words, tha resulto of any model will.only be as good as the data and/or assumptions incorporated r-in the model. Since, as we have shown in Ref. 3, the ,
i USGS model does not simulate actual physical proper, ties of the, groundwater system i'n the study area, the model cannot reliably predict groundwater " movements in Cowles Bog. The USGS Report therefore does not provide valid support. for any conclusion that its estimates of what "may occur" are accurate. .
- 5. The conclusion of Reference 2 states:
. "Because the flow model has not been verified, It can only be used in a general way to evaluate the effect of c6nstruction dewatering and' decline of the seepage mound on ground-water levels in and near the Lakeshore. Until the model-simulated estimates of water-level decline can be compared with measured declines, the I
accuracy of the simulated declines cannot be determined." "
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We would emphasize that this passage admits: the flow model 1
has not been verified and conclusions drawn from its use are therefore speculative. In fact, the actual field data shows that the model: is not valid. ..:.. J. t . t .
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Unite d States Depd$ent of the Interior d OFFICE OF THE ~ECRETARY ,M o 4, %
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7[h WASHINGTON, D.C. 20:40 November 26, 1980
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- M *-Q% d w.,g Memorandum
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Executive Secretariat To: , .
From: Richard N. Wilson, Special Assistant for Minerals Offic e Ass Energy and' Minerals
Subject:
Rep y Eugene l. Shorb, Northern Indiana Public Service Company, Concerning Bailly Generating Station Nuclear 1
. (ESif23340) .
. The Assistant Secretary for Energy and Minerals declines to surname this letter because it fail.s to respond to the points raised by Mr. Shorb concerning U.S.' Geological Survey's Open File Report _
80-1105, " Reassessment of the Effects of Construction Dewatering on Ground-Water Levels in Cowles Unit, Indiana Dunes *:ational Lakeshore, Indiana." In that the " inadequacies" cited by Mr. Shorb are highly tec inica1 in nature, the. Geological Survey should be given an opportunity to respond to them. We suggest the ietter be transferred to the Geological Survey for analysis and reply, and ,
we would be happy to draft an interim response to Mr. Sherb.
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EM:RNWILSON:bw:x38804:ll/26/80 D nport I!ECElVED Richard Wilson '
[USGS_ DEC 11980 CHIEE JiYDROLOGIST
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L. A A N. United States Depar$ent of the Interior b{g
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WASHINGTON, D.C. 20:40 'g" 1 November 2# 1980 1 x\
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Memgrandum -
To: Executive Secretariat . .
From: Richard N. Wilson, Special Assistant for Minerals Offic the As * .t Secretary--Energy and Minerals
Subject:
A4A 60l}'an~-
Rep y to Eugene I.. S tb, Northern Indiana Public Service Company, Concerning Bailly Generating Station Nuclear 1 (ES #23340)
- Tne Assistant Secretary for Energy and Minerals declines to surname this letter because it fail.s to respond to the points raised by
- Mr. Shorb concerning U.S.' Geological Survey's Open File Report .
80-1105, " Reassessment of the Effects of Construction Dewatering on Ground-Water Levels in Cowles Unit Indiana Dunes National Lakeshore, Indiana." Ir. that the." inadequacies" cited by Mr. Shorb
, are highly technica1 in nature, the. Geological Survey should be l given an opportunity to respond to them. We suggest the letter be transferred to the Geological Survey for analysis and reply, and ,
! we would be happy to draft an interim response to Mr. Shorb.
,. ,_ . . ;. - , .3 .,
EM:RHWILSON:bw:x38804:ll/26/80 '
cc: AS/EM (2)
. Ms. Davenport RECElVE.-u Richard Wilson .
(USGs l DEC 11980 CHIEE }{YDROLOGIST 9[
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- p.G.=;'- g* \ Unite d S tates Department of the Interior gp
--' OFFICE OF THE SECRETARY hl! #
WASHINGTON, D.C. 20240 e r .
10 November 1980 NOTE TO DIRECTOR, USGS i[V From: Joan M. Daven.Jo t Assistant Secretary-- ergy and Minerals Apparently the Northern Indiana Public Service company strongly disagrees with the USGS open file report " Reassessment of the Effects of Construction Dewatering on Ground-Water Levels in Cowles Unit, ,
Indiana Dunes National Lakeshore, Indiana, Supple-ment to Geological Survey Water Resources
. Investigations78-138." Given Chairman Yates's high interest in this area, I strongly suggest that ,
you obtain a copy of the D' Appolonia Consulting Engineers report. ,
Attachment RECElVEL nuv173999 l
CHIEF HYDROLOGIST
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. United States Department of the Interior 4 i,'
OFFICE OF THE SECRETARY dl #
s WASHINGTON, D.C. 20240 e r
i 10 November 1980 NOTE TO DIRECTOR, USGS 1[W From: Joan M. Davenpo t Assistant Secretary-- ergy and Minerals Apparently the Northern Indiana Public Service Company strongly disagrees with the USGS open file report " Reassessment of the Effects of Construction Dewatering on Ground-Water Levels in Cowles Unit,
. Indiana Dunes National Lakeshore, Indiana, Supple- .
l ment to Geological Survey Water Essources
- . Investigations78-138." Given Chairman Yates's l high interest in this area', I strongly suggest that ,
you obtain a copy of the D' Appolonia consulting
. Engineers report. ,
I Attachment RECEIVEL siuy171980
^
. CHIG HYDRO.0 GIST 1
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