TECHNICAL MEMORANDUM CUiHIlL · MEMORANDUM Page 2 February 3, 1994 The technical memorandum, containing such an analysis, will subsequently be used by EPA, in conjunction with the

T E C H N I C A L M E M O R A N D U M CUiHIlL

TO: Mark Doolan, RPM, Region VH EPA

FROM: Dick Glanzman/DENBill Bluck/BOI

DATE: January 5, 1994

RECEIVED

FEB 0- l ib-}

SPFD BRANCH

SUBJECT: Evaluation of Additional Remedial Alternatives for the Baxter Springs andTreece Subsites, Cherokee County Superfund Site

PROJECT: RME68062.ES

1.0 Introduction

EPA requested that CH2M HILL assist them in the development of a Proposal Plan (PP)

and subsequently, a Record of Decision (ROD) for the Baxter Springs and Treece Sub-

sites, portions of the Cherokee County, Kansas, Superfund Site. The PRP group has

completed for these subsites, a Remedial Investigation (RI) Report, Risk Assessment

(RA), and Feasibility Study (FS). EPA, in conducting its review of the FS, became

concerned that insufficient consideration had been given to development of remedial

alternatives that could significantly improve surface water quality, hence improve the

aquatic environment in the subsite tributaries and downstream receiving waters. Certain

alternatives, such as Alternative 5a that had considered these issues had been screened out

earlier in the FS process and, as a result, did not have the opportunity to be compared in

the detailed analysis of alternatives.

EPA directed CH2M HILL to 1) develop a detailed cost estimate for Alternative Sa using

the cost basis used in the FS; 2) establish a methodology to quantitatively judge the effec-

tiveness of this alternative in improving surface water quality as compared to Alterna-

tive 3; and 3) using such a methodology, try to develop an "additional" alternative that

would greatly improve surface water quality in a more costly effective manner than

Alternative 5a.

DEN100150E9.WP5

M E M O R A N D U MPage 2February 3, 1994

The technical memorandum, containing such an analysis, will subsequently be used by

EPA, in conjunction with the other project documents, to assist in the formulation of a

PP and subsequent completion of a ROD.

2.0 Methodology

2.1 Background

In the FS, a total of seven alternatives were carried through detailed analysis and com-

pared to the No-Action Alternative (noted as Alternative 1). The alternatives developed

were focused in reducing risks in two areas: 1) Public Health; and 2) "Ecorisk" as

judged by water quality measurements. Public health risk was reduced principally by

taking steps to reduce human exposure to contaminated mine waste materials to varying

degrees. Alternatives 2 and 3 considered actions at two residences. Alternatives 6a and

c, 7a and c and 8a added increasing levels of management of surface mine wastes, which,

in turn, added to the capital costs. Ground water impacts to public health primarily

consisted of prevention of contamination to the deep aquifer for all the remedial alterna-

tives. Institutional controls were also a portion of the actions to protect public health for

both source materials and ground water remedial actions. As regards ecorisk, ground-

water contamination of Willow Creek at the Baxter Springs subsite as a result of reducing

discharge from the Bruger Shaft was a component of alternatives, and was included under

groundwater remedial actions.

The main component of ecorisk improvement covered in the range of alternatives that

was developed in the FS for detailed analysis dealt principally with removal of outwash

tailings in four tributaries: Willow Creek and Spring Branch Creek at the Baxter Springs

DEN100150E9.WP5

MEMORANDUMPage 3February 3, 1994

Subsite and Tar Creek and Tar Creek Tributary for the Treece Subsite. The removed

outwash tailings would be relocated to nearby tailings deposits which would also be stabi-

lized, capped, regraded and revegetated. In addition to these actions, erosion protection

utilizing stream channels, dikes and diversion ditches would be installed. Short term

water management and sediment control would also be utilized during the construction

phase to protect water quality. Essentially, all the alternatives carried forward into

detailed analysis, except the No-Action and Alternative 2 (which was primarily a public

health only alternative), considered this level of surface water protection. No opportunity

existed in the detailed analysis to further compare and contrast alternatives that contained

other additional actions that would improve surface water quality, thus decreasing

ecorisk.

2.2 Unit Cost Development

In Section 6.4 and Appendix D of the FS, individual components of the remedies under

consideration are described and costed. It should be noted that the costing of Alterna-

tive Sa and development of the "additional" alternative will have certain common com-

ponents with Alternative 3, namely Source Material and Groundwater actions. Also, in

Chapters 1 and 5 of the FS, descriptions of the various mine waste units and areas were

designated, including those that were deemed "largest" as well as those designated as

"significant" contributors to added metals loading to various tributary surface waters.

See Drawings No.'s 1.6-1, -2, and -3 as well as 5.2-1 and -2. Appendix A further item-

ized various waste units and areas. Consequently, these referenced sections of the FS

were used to develop the component elements shown in Table 1, Detailed Costs of

Alternative 3.

Note that the specific item numbers with their respective unit costs, and individual mine

waste units were designated for each of the four major tributaries of interest.

DEN1001SOE9.WP5

Una Daeriptioa

1.0 SoncoMamM Action

1 . 1 Ruidenlul toum removal aclioni

1.2 Injtilulionil contrail

Subtotal!

2.0 Oraundwalcr Aciiona

2.1 Deep iqiiibr well plut

2.2 Brager theft coraiol

2.3 OrwindwattrintfiUHionilcortroli

-Sutrtotale

3.0 Surface Wafer Action

3.1 Fill, cap, ragrade, >nd rcvcftution

uilin|apilea

3.2 Removil/diipoeeofoiitwaahuili

3.3 Stream chlimllutraa

3.4 ErahncoMraMiwreloiiililchei

Unit Costm

31,000 ei

100,000 ra

73,636 ei

11.000 ea

100,000 ««

39.359/tt

HMIjf

Conv.to3I.750/K

IS5.00/LP

•H-WLf

TJ.U 1DcUOcd Com- AHcraidT* 3

Outer Spriegi

Spring Bruch

(1)

(1)

0)

-

0)

BT-23(3.Wic), BT4(I0.4I ic)

BT-2,(6.26 K), BT-7(0.« K)

BT-8(3.53 ic), BT-9(I.04 u)

Toul -25.35 K

BOW-I (24.19 «c>-BT6, 7, 1, ud 9

BOW-4 (9.71 K>.gT-23

Toul-33.9*c

1,000' new BTT22 >nd breech ofBT23 cepiired

500 LF

Willow Cmk

N/A

N/A

N/A

(1)

N/A

BT-M4.07 K)

Trt.l-4.07ic

BOW-1 (1.36«c)mdBOW-3(1 1.17*0

-HT-I

Taul-I3.23ec

Nil

Nil

r*Sel«f2

Traett

TnrCretk

(1)

(1)

(1)_

(1)

TT-IO(IO.lK), TT-1I(I.5 ac)

TT- 14 (7 .96 ec)

Toul -20.26 ic

TOW-1 (I.I «c) ind TOW-2(2.5 K) end TOW-5 (0.22 ic)

-TTIOuidM

Toi>l-3.12 K

100' of channel end riprapnorth TT-I end dike npeir

9 TT-I 1 Md 22

500 LF

T.C. Tritntaiy

N/A

N/A

N/A

-

N/A

TT-2I(4.73ec)

Toul-4.73 ec

TOW-3 (9.13 K) end TOW-4(2.22 Kh>TT22

Toul-ll.35ac

Nil

BntarSpifad

Com0)

35,000

100.000

135,000

220,901

11,000

100,000

40J.90I

1,157,942

I,<I4,19I

115.000

11,000

Tnecc

Comm

35,000

100,000

135.000

519,0(1

0

100,000

M9.0II

913,511

542.321

141.000

11.000

DENIOOI4FF3.WP5

lion Docripltai

1.S Dik.1 ind embndmenu

3.6 ScdimenUlionbMini

3.7 Pond witcr hindlhn;

SubtaUli

4.0 Subutil-DlreclCotfi

5.0 Indirect COM

3.1 Enf incctinf OCMfn

3.2 Conitiuetlon miiuftimnl

5.3 Conlinftncjr

Subtouli

6.0 Toul Coil Eitiimta

TeUlCdft

IteftCoit($)

21.00/LF

47.397 n

26.070An|d

6* of 4.0

12.7X of 4.0

23.73* of 4.0

TikklDfUiI«I CnU-Allen»(lTe3 P i 2 of 1

BucttrSpri i

Spring Branch

500 LF

(1)

1 mf d

Willow Cratk

Nil

(I)

Imfd

Trace*

TarCmk

3,800 LF

(I)

0.5 mgd

TJC. Tribilny

Nil

(I)

0.5 mfd

ButarSpriMi

Coitt($)

14,000

94.794

52,140

3.199.774

3,743,682

224,621

475,441

SS9.I24

1,589,193

5,332,875

Tram

Cots($)

106.400

94,794

26.070

1,912.173

2.736.261

164,176

347.505

649,162

1.161,543

3.197,104

9.230,679

DEN 10014FF3.WP5

MEMORANDUMPage 4February 3, 1994

2.3 Alternate 5a Cost Estimate

With the unit costs and specific mine waste units established by tributary for both the

subsites, the next step was referral to Section 5.2.3.5 of the FS to assist in the develop-

ment of Table 2, Detailed Costs of Alternative 5a. This alternative, along with others in

the FS, focused on additional methods to improve surface water quality of the various

tributaries by mine waste consolidation and other means, and, as mentioned earlier, had

been screened out so that they could not be further evaluated.

It should be recalled that surface water actions for Alternative 3, focused primarily on

removal of outwash tailings in the four tributaries and consolidating them in key tailings

deposits along with limited channelization, dikes and other surface water management

functions. Alternative 5a, on the other hand, considered remediating virtually all mine

waste units and areas considered the "largest" and "significant" contributors to metals

contamination of this tributary, in addition to that done with alternate 3. This alternative

offers a reasonable upper-bound, or ultimate solution, as regards potential remediation of

mine waste units and areas that clearly degrade surface water quality. As can be seen in

Table 2, appropriate mine waste units/areas were noted for each tributary and, using the

unit costs developed in Table 1, capital costs were then calculated. Indirect costs, for

engineering, construction management, and contingency using the same percentages of

direct costs that were utilized in Alternative 3. Also, source material actions and ground-

water actions were identical to that utilized for Alternative 3. Including these additional

"significant" and "largest" mine waste units to be remediated added over $10.3 million to

the capital cost, compared to Alternative 3, bringing total estimated capital costs to

$19.6 million.

DEN100150E9.WPS

Table!Detailed CoU- AlteruliTC Si

(Sn VS. SecooB 5 J 3 S ud Appendix A) Fa** > «' 1

tan Docrlpooa

1.0 Source Materiel Acton

2.0 Groundwatcr Action

1.0 Surface Water Action

3 . 1 .. FiH, up, Kfnde, in) icwfcliflai tallhifapiki

3. 1 .b Additional 'ilfiririCMl' tailing! nfraded.recantoured, capped, and nvtgcbkd

3.1 jc •SifniricMl- chat pllu, would b*icgavdad, ncooloiiiM, cappM( andRTC|etated

3.1 jt- -Sltnlfleanl' «carattd chat piUa wouldD9 ICf nOCfl •fid |WCfCUltC4

3.2 RamoK/diapOMofoulwaahUili

Unit Cart($)

39.1S9/M

39459/ic

13,410/ac

1.905/ac

11.00/yd1

or35,750/ic

Hauler Springi

Sprioc Braock WinowCndi

Santa ai Ahentalive No. 3

Santa ai Akcmalm No. 3

Same at Allemi

ToUI-Z5.35ac

BT.4 (1 .47 ac)

Tolal-l.47ac

BC-l2(53.l2ac)

ToUl-53.82 ac

BX-II(3.99A) +BX-290.79A) +BX-3I(2I.S4A)

Santa aa Ancrna

Toul-33.9A

ire No. 3

Total -4.07/ac

Nil

Nil

Nil

iv* No. 3

Total -13. 23 ac

Traece

T«r Creek T.C. TriboUry

Same ai Alternative No. 3

Same tl Ahcmaliwe No. 3

Same aa AHei

Tool- 20.26 «c

TT-5(2.42A) + TT-6 (2.46 A) +TT-«(32.92A) + TT-IO(IO.SA) +TT-I4(7.96A) + TT-30(O.Mac) +TT-3l(7.62ac) + T-32Q.57A) +TT-4I(6.26A) + TT-44(3.66ac)

T<K.I-77.5l.c

TC-3(50.76A) + TC-4(20.2A) +TC-7(6.67A) + TC-9(40.04A) +TC-I5,.(24.8IA) + TC-6H(17.35A)+TC-29(3.15A) +TC-37(eit. 2.0 ac)

Total- I64.9lac

TX-704.09A) + TX-16(5.94A) +TX-21(II.7A) + TX-5(I0.52A) -fTX-29(22.04A) + TX-30X2.7A) +TX-3I(II.79A) + TX-32(6.7IA) +TX-39(22.6A)

Same ai Altai

SI-3.R2A

mliva No. 3

Toul-4.73 ac

TT-17,,(S.13 ac) + IT-ISO .343A) + TT-I9(I.MA) +1T-2I(I.36A) -f TT-4K3.MA)

Toul-ll.l2ac

TC-20 (3.09A)

TouU-3.09ac

TX-20(I.2IA).TX-42(9.77A) +TX-43(19.7IA) 4 TX-46<O.JA<at.)

native No. 3

Total- II.35A

BaxterSorinfi

Comm

135.000

401.901

1.137.942

57,151

721.726

1.6*4,898

Tnecc

Comm

135,000

619,011

9(3,511

3,167,106

2.253.S19

542,321

DEN100I4FP1.WF3

Hen Dacrlptioa

3.3 Stream channelization

3.4 Eration conlrol/divenioB ditchtt

3 .5 Dikci and embankmcnti

3.6 Sedimentation batine

3.7 Pond witer handlinf

Subtotal

4.0 SubtoUl- Direct COM

5.0 Indirect Com

5.1 Enfineerinf

5.2 Conttniction Management

5.3 Contingency

Subtotal

6.0 Toul Co* Enim.lt

Total Cut

IMtCott($)

1S5.00/LF

22.00/LF

2S.OO/LF

47,397 ca

26.000/mgd

6* of 4.0

12.7»of4.0

23.75 *of4.0

Table 1Detailed Com- Alternate 5a

(See FS. Strtloo 5 JJ.5 and Appendix A) rage 2 of 2

Baxter Spring*

Sprat; Branch

Same at Alleraa

Total -1, 000 LF

Willow Creek

iveNo. 3

Same at Ahemative No. 3

Same ai Ahcmalive No. 3

Same n Allcnwlivt No. 3

Same aa Allemalin No. 3

Trace

Tar Crack

100' (All. 3 + 1,000' TT-I

Toul -1, 800 LF

T.C. Tributary

Nil(Ail. 3) + 500' fcrTT-U. 19

Total-500 LF

Same at Alternative No. 3

Sam at Alternative No. 3

Same at Alternative No. 3

Same at Alternative No. 3'

BaxterSpriafi

Com(S)

185,000

11.000

14.000

94.794

52,140

4,035,213

4.J79.I2I

274,747

5II.54S

1.017,541

1,943,836

6.522.957

Trcccc

Cam(J)

425,500

11.000

106.400

94.794

26.070

1.327.495

9,151.583

549.095

1.162.251

2.173,501

3,114,147

13,036.430

19.5594*7

DENIOOI4FFI.WP5

M E M O R A N D U MPageSFebruary 3, 1994

2.4 Determination of Effectiveness

It was then necessary to develop a method, using existing RI data, to assess whether the

addition of these actions which added over $10 million to the cost to Alternative 3 was a

cost effective action or not. These subsites are very large and the weathering and

oxidation of the various minerals from many different mine wastes as influenced by pre-

cipitation, physical location, and other factors, complicates the ability to measure these

changes and subsequently understand how these systems behave in detail, particularly

when the difference between "good" or "bad" is measured in parts per billion. The

extensive data base generated during the RI/FS process was again reviewed to find a

means to assist making this judgement and it was decided that about the only approach

practical would be based upon the zinc mass load measurements found in the FS, notably

summarized, in Figures 1.6-2 and -3, and based upon the hydrology of the tributaries.

As is noted in the FS, the Willow Creek and Spring Branch tributaries are relatively

small flow and contaminant mass load contributors to the Spring River near Baxter

Springs, compared to the river as a whole. Tar Creek and Tar Creek Tributary near

Treece, carry about 10-times the zinc loads by comparison to Willow Creek and Spring

Branch. When referring to Figures 5.2-1 and -2, it becomes very apparent that the quan-

tities and aerial extent of the various mine wastes are much greater in the Treece area so

it makes some sense as regards the differences in the mass loads from each.

In order to make comparisons of effectiveness between Alternatives 3 and Sa, it was

decided that, by utilizing the zinc mass load data for each subsite developed during the RI

and estimating mass load reduction based upon remediation of specific mine waste units/

areas, relative estimates of reduction of zinc loads could be made. Some professional

judgements had to be made in making minor adjustments to make the comparisons.

Calculations for the estimated zinc mass load reductions for Alternative 3 and Alterna-

tive Sa can be found in Appendix A. Since the remedies actual effectiveness is difficult

DEN100150E9.WP5

Table 3Mass Load Reduction and Effectiveness Estimate— Alternative 3

Description

• Zinc Mass load - noaction (Ibs./day)

• Load Reduction -Alt 3©100% efficiency@ 85% efficiency@ 65% efficiency

• Capital Cost - Alt 3items 3.1, 3.2,3.3CTable 1)

• Cost/lb. of zinc/persubsite reduction(85% efficiency)

• Weighted averagecost/lb. for bothsubsites@ 85% effectiveness

Baxter Springs

507 Ibs./day

216 Ibs./day184 Ibs./day140 Ibs./day

$3,028,840

$16,461/lb.

Treece

4,693 lbs./day

110 Ibs./day94 lbs./day72 lbs./day

$1,673,909

$17,808/lb.

$16,916

DEN100150F1.WK

Table 4Mass Load Reduction and Effectiveness Estimate -Alternative 5a

Description


• Load Reduction -AltSa©100% efficiency@ 85% efficiency@ 65% efficiency

• Capital Cost - Alt 5aitems 3. la, b, c, d,3.2, 3.3 (Table 2)

• Cost/lb./subsite ofzinc reduction(85% efficiency)


Baxter Springs

507 Ibs./day


$3,863,279

$9,586/lb.

Treece

4,693 Ibs./day

4,585 Ibs./day3,898 Ibs./day2,980 Ibs./day

$8,089,231

$2,075/lb.

$2,779/lb.

DEN100150FI.WP5

M E M O R A N D U MPage?February 3, 1994

2.6 Development of a More

Cost Effective Alternative

It can be seen, however, that the effectiveness of spending considerable monies in

remedying outwash tailings in the four tributary drainages as part of Alternative 3, is

really not very cost effective since the data clearly indicates that these wastes are not

truly significant contributors to the degradation of surface water quality. This fact was

considered in subsequently assessing additional engineering actions specifically geared to

improving surface water quality for the next phase of the work. During the development

of this report, discussions were held with EPA representatives regarding other concerns

that they have regarding outwash tailings. Although these concerns became more qualita-

tive than quantitative in nature, there is evidence to support the following:

(a) The outwash tailings do have elevated metals concentrations and pose

potential health risks via inhalation or ingestion while people recreate in

these drainages.

(b) The outwash tailings, if uncontrolled, will continue to add sediment and

dissolved metal loads to downstream reaches of the tributaries and subse-

quently to the Spring and Neosho Rivers and therefore pose ongoing

adverse threats to macroinvertebrates in the ecosystem.

Given these factors, it became apparent that remediation of the outwash tailings in all

four tributaries should be included in the subsequent development of a surface water

quality improvement remedy that is more cost effective and fits somewhere between

Alternatives 3 and 5a.

DEN100150E9.WP5

M E M O R A N D U MPageSFebruary 3, 1994

Referring back to FS Figures 1.6-3 and 5.2-2, it can be noted that the big load increase

occurs in the Tar Creek drainage between stations TC-1 and TC-2 where mass loads

increase from 36 Ibs/day to 3,674 Ibs/day or over 81 percent of the whole drainages'

mass load. Almost all of the identified mine waste areas were designated as "largest"

according to the FS. From station TC-2 to TC-3, the gain in zinc is over 800 Ibs./day

with one additional "largest" mine waste source noted (TT-8). It was therefore decided

to modify Alternative 5a to only remedy the mine waste areas designated as "largest"

rather than both varieties and include remediation of the outwash tailings as did Alterna-

tive 3 and 5a. A subsequent cost estimate for Modified Alternative Sa was developed and

is noted as Table 5. Capital cost for this alternative was determined to be approximately

$13.36 million or about $4.1 million more than Alternative 3 and about $6.2 million less

than Alternative Sa. A similar mass load reduction and effectiveness estimate for this

alternative was developed and is noted as Table 6. As can be seen, weighted cost/pound

for zinc reduction drops to $2,283 per pound. Details of the estimate are found in

Appendix A.

2.7 Development of Operating and

Maintenance Costs and NPV Calculations

In addition to the capital cost estimate for each alternative, EPA guidance requires that

annual operating and maintenance costs (O&M Costs) be developed for each alternative in

the detailed analysis. In addition, for each alternative, a present worth or Net Present

Value (NPV) calculation is also conducted on the combined capital and 0 and M costs for

a 30-year period using a 5 percent discount rate. In reviewing the FS, it appears the

present worth was calculated on a 5-year basis rather than 30-years. Both time frames

will be calculated so guidance is met but comparability to the FS can be measured as

well.

DEN100150E9.WP5

lien Dncriptln

1 .0 Source Material Aclioni

2.0 Oraundwiitr Aclion

3.0 Surface Water Actions

3.1« Per All H - Till, cap, rcgrede. indrevegelale tailing! piki

3.lb Add 'larger!- Irili to fill, regrade,revegeute

3.1c Add -largeM- chat pilci lo be rcgraded,recomoured, capped and icvcfeuied

3. Id Add -|arge«r excavated chai pilca lo beregcaded and revegetaled

3 .2 Removal/diapoic of outwith Mill

3.3 Slitam channelizalion

3.4 Ereiion control/divenion dilchet

3.5 Dikci and cmbankmenli

3.6 Sedimenlationbaaina

3.7 Pond water handling

Subtotal*

4.0 Subtotal -Direct Com

5.0 Indirect Com

TibatSModified AltenaitiTC 5« Page 1 of 2

UACoMIS)

39.359/ac

39.359/ac

13,410/ac

1,905/iC

ll.OO/ydor

35.750/ac

185/lf

22/ir

28/ir

47.397 ea

26,070/mfd

Baxter Sprfaiip

Sprint Branch Willow Cntk

Same aa Alternative 3

Same af Alternative 3

Same ai AllernTotH2i.J5.A

nil

nil

nil

Same at Ahem

33.9 ac

1,000 LF

500 LF

500 LF

(1)

1 mgd

live 3T<nal-4.07A

nil

nil

nil

Hive 3

13.23 ac

nil

nil

nil

(1)

Imgd

Trace*

TarCmfc T.C. Tributary

Same ai Alternative 3

Same ai Alternative 3

Same aa ATotil-20.26A

TT30(.84) + TT3 1(7.62)+TT32(2.57) + TT33(.7I) +Tn(32.92)Total-44.66ac

TC3(J0.76a) + TC29(24.4a)Total -75.1 6 ac

7X7(34.05) + TX29(24.4) +TX3I (11.79.),Total -70.28 ac

Same aa A

3.82 ac

IOOLF

500 LF

3,«(K) LF

(1)

0.5 mgd

tlemative 3Toul-4.73A

nil

nil

nil

lemalive 3

lt.35ac

nil

nil

nil

. 0)

0.5 mgd

Baxter Sprig*?

Coils($)

135,000

408,908

1.157,942

I.684.S98

1(5.000

11,000

14,000

94.794

52.140

3.199.774

3.743,612

Trent

Com($)

135,000

689,088

983,581

1,757,773

1,007,896

133.884

542.338

148,000

11,000

106,400

94,794

26.070

4,811,726

5,633.114

DENIOOI50F3.WP5

TiMcSModified AllcnMli*«5i P^ctoTl

lloa DocripliM

5.1 EminMrinfdoifn

5.1 Contraction imnifuneRl

5.3 Continfencjr

SubtoUli

6.0 Total Co* Ediimt*

ToUlCoft

UoilCnt(S)

6* of 4

!2.7«of4

23.75* of 4

BwrtcrSprfaKi

Spriag Branch Wiltew Cnch

Tram

TcrCntli T.C. TribuUiy

•wtar Sprajci

Cab($)

124,621

475.441

189,124

1,519.193

5,332,875

Tram

CnuIS)

338,149

715.741

1,338,506

2.392.403

8.028,117

134*1,092

DEN100IJOF3.WP5

Table 6Mass Load Reduction and Effectiveness Estimate-Modified Alternative 5a

Description Baxter Springs Treece


507 Ibs./day 4,693 Ibs./day

Load Reduction -Alt5§

@ 100% efficiency@ 85% efficiency@ 65% efficiency


3,701 Ibs./day3,146 Ibs./day2,406 Ibs./day

Capital Cost -ModifiedAlternative 51 items3.1a, b, c, d, 3.2, 3.3(Table 5)

$3,027,840 $4,573,462

Cost/lb. of zincreduction (85%efficiency)

$16,456 $1,454


$2,283/lb.

DEN100150F1.WPS

M E M O R A N D U MPage 9February 3, 1994

Upon further review of the FS, it was not possible to determine the basis of the O&M

costs used for Alternative 3 that could then be carried forward for the two other alterna-•s

lives under consideration. Therefore, an independent estimate was developed and is

shown in Appendix B. Operating and Maintenance Costs along with the capital costs are

summarized as follows along with present worth costs for a 5-year and 30-year period are

shown for all three alternatives in Table 7.

Table 7

Capital and O&M Summary of Costs

Capital Costs

O&M Costs (5 year)

Present Worth (5 year)

Present Worth (30 years)

Alternative 3

$9,230,679

360,437

9,513,091

10,233,424

Alternative 5a

$19,559,387

722,926

20,125,818

21,570,586

Modified

Alternative 5a

$13,361,092

505,365

13,757,059

14,767,031

3.0 Comparative Analysis

The levels of overall protection of human health and the environment attainable with

implementation of each of the three remedial alternatives are summarized and compared

in Table 8.

DEN1001SOE9.WPS

Table 8Comparative Analysis of Alternatives Page 1 of 3

Criteria/Description Alternative 3 Alternative 5a Modified Alternative 5a

1. Protection of Public Health andthe Environment

A. Source Materials

Human Health Risks

Environmental Risks

Assuming institutional controls areimplemental and enforced,Alternative 3 would minimize risksassociated with current and futureexposures to source materials.Removal and consolidation of outwashtailings reduces risk to recreators.

Risks to macroinvertebrates and otherterrestrial biota will be reduced due toremoval of outwash tailings and somecontrol of their sources.

Same as Alternative 3 Same as Alternative 3


B. Groundwater

Human Health Risks

Environmental Risks

Assuming institutional controls areimplemented and enforced,Alternative 3 would prevent futurehealth risks from consumption ofshallow groundwater. Protection ofdeeper aquifer addresses hiturepotential risks.

Remedial actions at Broger shaft toreduce environmental discharge toWillow Creek will reduce contaminantloading to Willow Creek, that maycontribute to infrequent exceedances ofTRVs in portions of Willow Creek.



Surface Water

Human Health Risks No risks to human health are attributedto surface water.


DEN10015142.WP5


Criteria/Description Alternative 3 Alternative Sa Modified Alternative 5a

Environmental Risks Removal of outwash tailings andstabilization of major sources ofoutwash tailings will reduce zinc (andother metals) loading to the Spring andNeosho Rivers by about 5 percent. Itcannot be determined if TRVs orAWQCs could be met in variousreaches of the tributaries on acontinuous basis.

Removal of outwash tailings andreclamation and/or .stabilizationof all other "largest" and"significant" mine waste sourceswill reduce zinc (and othermetals) loading to the Spring andNeosho Rivers by about83 percent. It is very probablythat major improvements in waterquality will result than withAlternative 3 but it cannot bedetermined that TRVs orAWQCs could be met in variousreaches of the tributaries on acontinuous basis.

Removal of outwash tailings andreclamation and/or stabilizationof "largest" mine waste sourceswill reduce zinc (and othermetals) loading to the Spring andNeosho rivers by about64 percent. It is probable thatthere will still be dramaticimprovements in water qualitybut less than Alternative Sa andagain, it cannot be determinedwhether TRVs or AWQCs couldbe met in various reaches of thetributaries on a continuous basis.

2. Will Remedies Meet ARARs? See Subsection 7.1.2 of F.S. Doubtfulthat zinc reduction significant to meetTRVs or AWQCs.

Same as Alternative 3 but zincload reduction very significant.Cannot determine if TRVs orAWQCs can be met.

Same as Alternative 3 but zinclead reduction significant.Cannot determine if TRVs orAWQCs can be met.

3. Long-Term Effectiveness andPermanence

Magnitude of ResidualRisks

If institutional controls implementedand enforced, current and futureresidual risks will be minimized.Removal of outwash tailings reducesrisk to recreators and reduces ongoingcontaminated sediment loads toreceiving waters.

Surface water quality improvementsminimal based on small zinc loadreductions.

Same as Alternative 3 Same as Alternative 3.

Major surface water qualityimprovements expected intributaries.

Significant surface water qualityimprovements as great asAlternative Sa.

DEN10015142.WP5


Criteria/Description

Adequacy/Reliability ofControls

4. Reduction of Mobility,Toxicity, and Volume ThroughTreatment

5. Short-Tenn Effectiveness

Protection of LocalCommunities, WorkerProtection, EnvironmentalImpacts

Time Required to ReachRemedial Goals

6. Implementability

7. Cost

Capital CostsBaxter Springs

Treece

Total Capital Costs

Annual O&M Costs

Total Present Worth (30 yearsat 5 percent discount)

Total Present Worth (5 Yean atS percent discount)

Alternative 3

Proposed engineering methods areadequate and reliable. Potentialdisturbances of capped materials couldresult in future risks.

Not applicable

Potential short-term risks tocommunities, workers, andenvironment are manageable andacceptable. Some siltation will occuras a result of outwash tailings removal.Alternative 3 could be completedwithin 2- to 3-year time frame withongoing post-remediation O&M forforeseeable future

Alternative 3 is Technically Feasible.Proposed institutional controls areimplernentable. All materials andservices are readily available.

$5.333 million

$3.898 million

$9.231 million

$72,087

$10.233 million

$9.513 million

Alternative 5a

Same as Alternative 3

Not applicable


Same as Alternative 3 butcompletion about 4 to 5 years.


$6.523 million

$13.036 million

$19.559 million

$144,585

$21.571 million

$20. 126 million

Modified Alternative 5a


Not applicable


Same as Alternative 3 butcompletion about 3 to 4 years


$5.333 million

$8.028 million

$13.361 million

$101,073

$14.767 million

$13.757 million

DEN10015142.WP5

Appendix AZinc Mass Load Calculations

I. Base Case - Baxter Springs (Figure 1.6-2 basis)

A. Spring Branch

(Note load loss between SB-1 and SB-2)

• Use SB1 and SB1A as basis (conservative) = 456 Ibs./day

• SBA1 @ 11 Ibs./day, SBA2 @ 60 Ibs./day(438 Ibs./day from lower outwash area)

B. Willow Creek

• WC-1 @ 51 Ibs./day

• Most load upgradient of station WC-1A (38 Ibs./day)

C. Total - use 456 + 51 = 507 Ibs./day into Spring River

n. Base Case - Treece

A. Tar Creek

Upgradient TC-1 @ 36 Ibs./dayTC-1B @ 923 Ibs./dayTC-2 @ 3,674 Ibs./dayTC-3 @ 4,479 Ibs./day

B. Tar Creek Tributary

TT-la @ 29 Ibs./dayTT-1 @ 214 lbs./day

C. Total - use 4,479 + 214 = 4.693 lbs./day

DEN100150EA.WK A-l

Alternate 3 - Reduction Estimate

Baxter Springs

Willow Creek -

Spring Branch -

Total reduction

if remedy 100% effectiveor

if remedy 85 % effective =or

if remedy 65% effective =or

Based upon outwash tails BOW-1 and BOW-2. Intributaries where maximum load reduction at 100%efficiency would equal 36 Ibs./day Zn.

•Based upon outwash tail BOW-2, area to beremediated is (33.9 + 25.35) 59.25 Ac out of 143.86Ac deemed to be "significant" or "largest."Assuming reduction proportionate to area, maximumload reduction would be

x (449-11) = 180 Ibs./day Zn

216 Ibs./day43% reduction



Treece

Tar Creek Drainage - Based upon outwash tails TOW-12 and 2, area tobe remediated totals 24.08 Ac from a total minewaste area of 395 Ac (6.1%). About 222 Ac isbelow TC-2. In this drainage, 82% (3,674Ibs./day Zn) comes from above station TC-2.Again, assuming load reduction proportional toaffected area remediated, the remaining 18% ofthe mass load (805 Ibs./day) may be reduced by/(24.08Ad\\ 222 Ac / 10.8% or 87 Ibs./day

Tar Creek Tributary -Calculations on same basis yields IMS

70.55 23 Ibs./day

DEN100150EA.WP5 A-2

Total reduction




IV. Alternate 5a-Reduction Estimate

110 Ibs./day2.3% reduction



We will use the same load reduction estimating basis as done for alternative 3.Since this remedy deals with all "largest" and "significant" defined sources, it isassumed that other minor waste units contribute no load and ignores theupgradient mass loads (assumes they pass through).

For Baxter Springs

Willow Creek (same as alternate 3)

Spring BranchAll 143.86 Ac will be remediated

Tar Creek Tributary - 70.55 Ac willbe remediated

= 36 Ibs./day reduction

= 438 Ibs./day reduction

= (214 - 29) = 185 Ibs./dayreduction

If remedy 100% effective = 4,585 Ibs./dayor 98% reduction

If remedy 85% effectiveor


3,898 Ibs./day83% reduction

2,980 Ibs./day64% reduction

DEN100150EA.WP5 A-3

V. Modified Alternative 5a-Load Reduction Estimate

We will use same basis of load reduction used for alternative 5a.

Baxter Springs

Willow Creek (same as alternate 3)

Spring Branch (same as alternate 3)




Treece

Tar Creek Tributary(same as alternate 3)

Tar CreekOutwash Tails Benefit(same as alternate 3)

Reach TC-1 to TC-2

"Largest"

36 Ibs./day reduction







TT-33TT-30TT-31TT-32TC-3TC-29TX-7TX-29TX-31Subtotal

TX-32Total

0.71 Ac0.84 Ac7.62 Ac2.57 Ac

50.76 Ac3.15 Ac

34.09 Ac22.04 Ac11.79 Ac

133.57

6.71 Ac140.28 Ac

"Significant"

% waste area to be remediated -122.57 -r 140.28 = 95%

DEN100150EA.WP5 A-4

Station TC-1 to TC-2

If remedy 100% effective

Reach TC-2 to TC-3

.95 x 3,638 - 3,456/lbs. day reduction

"Largest"Subtotal

"Significant"

Subtotal

Total

STA TC-2 to TC-3

TT-8

TC-1 6TC-15TC-9TC-37TC-7TC-4TX-25TT-5TT-6TT-41TX-25TX-39

If remedy 100% effective

32.92 Ac32.92 Ac

17.35 Ac24.81 Ac40.04 Ac

? Ac6.67 Ac20.2 Ac

10.52 Ac2.42 Ac2.46 Ac6.26 Ac

10.52 Ac22^ Ac

163.85 Ac

196.77 Ac

= 3.2,92 gQ5

196.77 ™135 Ibs./day reduction

Treece Summary

23 Ibs. + 87 Ibs. + 3,456 Ibs. + 135 Ibs. = 3,701 Ibs./day reductionif 100% effective

If remedy 85% effective = 3,146 Ibs./day reduction

If remedy 65% effective = 2,406 Ibs./day reduction

DEN100150EA.WP5 A-5

Appendix BO&M Cost Estimates

Assumptions

1. Source Materials Actions:

• One residence each at Baxter Springs and Treece - assume normalmaintenance done, by homeowner.

• Sampling done once/5 year period to monitor for each site.Labor and analytical cost-SlO.OOO all alternatives.

2. Groundwater Actions

• Deep well plugging-assume some inspection and well maintenancerequired once in 5 years representing 5% of capital cost.5% (11 @ 73,636/ea) = S40.500 all alternatives.

• Bruger Shaft - assume one time repair over 5 years @ 10% ofcapital cost = $8.800 all alternatives.

3. Surface Water Actions

a. Annual Inspections-2 engineers/1 week/® $l,000/day = $5,000 allalternatives

b. Assume for a given remedy, one fifth of the sites require some regrading,reseeding, including stream channels, dikes and embankments. Costs areestimated to be 5% of installed capital costs (items 3.1, 3.2 and 3.3) foreach alternative over a 5 year period.

Alt 3 - .05 x $4,702,749 =$235,137

Alt 5a - .05 x $11,952,510 = $597,626

Modified Alt 5a - .05 x $7,061,302 = $380,065

c. Surface Water Sampling and Analysis

Four sample rounds/year @ 12 mandays each plus analytical costs.Five years total5 [4x12 mo @ 150.00/md + 5,000 annually] = $61,000 for eachalternative.

DEN100150ED.WP5 B-l

Summary of 5 year O&M Costs

Alt 3 Alt 5a Atl 5a

1. Source Material 10,000 10,000 10,000

2. Groundwater 49,300 49,300 49,300

3. Surface Water

a. Inspections 5,000 5,000 5,000

b. Repairs 235,137 597,626 380,065

c. Sample & Analysis 61.000 61.000 61.000

Total 5 year costs $360,437 $722,926 $505,365

DEN100150ED.WP5 B-2

Documents

TECHNICAL MEMORANDUM CUiHIlL · MEMORANDUM Page 2 February 3, 1994 The technical memorandum, containing such an analysis, will subsequently be used by EPA, in conjunction with the