OFFICIAL DOCKET COPY · submit an amendment request to NRC Source Material License SUA-1471. In fulfill ment of i1cense condition -315D Homestae.. sonits, .cr NRC ... layout of the

6~96 33~J~~ HOMESTAKE MINING COMPANYP.O. BOX 98GRANTS, NEW MEXICO 87020

(505) 287-4456

June S. !g§0 •Oi !13,

Mr. Ramon . Haul, Dnre1ctor

Uranium Recovery Fields ,f I -U.S. Nuclear Regulatorv Commission ....7.3.,0 Simm s Se, tu-te +10%Golden, Colorado 00401

Re Evapor-ation Pond Design Specif icationsfor NRC Source Material License SUA-1471

Dear Mr. Hall.

Homestake Mining .omp.an of California (Homestak-, takes this o-pportuity tosubmit an amendment request to NRC Source Material License SUA-1471. Infulfill ment of i1cense condition -315D Homestae.. sonits, .cr NRC's considerat.the attacned evaporati.on pond design specifications and $150 for the amendmentfee.

The proposed evaporAtcn pond Is desi. 1 ned to be 1 cateu on the small rnact:. etailing facility. Homestake has determined t-he small tailing facilit.(considered Atcmi c Prie ry Ccommission ta il i njg by Hoi'cnes t ict sui 4 .a.b .sit

meetina a esign criteria for an evaporation pond.

Hoestake conside..rs the roposed eva.porat-ion '-o i .s a. n itn a: step i ..t..reclamation of tailingacilties located at. the HomestaKe mill. Althcvghthe current proposed evaporati.on pond is smaller than the or-iginal design inl thereclamation plan, enhanced evaporation through the use of spray misting wilcompensate for the ,ifrn.e in surFace area. The pr.p,-o evaporation pcdis expected to evaporate approximately 350 gallons per minute. The a+tacheddesign speci ci cation..s di spl ay the e.v.poraton sp rpay 3sytrn an, . a e d l ocatins .Homestake views the evaporation spray systems as an operational function ratherthan a design criteria. Te exact des-gn and ope-rati-F tlhe spray systes, wi.Cha an des•t~ r ..n; the -:re, o, -m.'.l a . hixa tUI ý !

be based upon avaij able resources and maximum e'ficency.

Homestk.t<.e expects-t.4, to0 use the proposed. evaporation pond as the Iain a:'-e f:.rdisposal of waters.. The amount and types of water to oe placed in the proposedevaporatio'.. n ,,-;r, pond w-'-11 depend on e ..... ' ,- . t l u,.precipitation caused cy the mi",ing of waters. Trhe f•ow directior and mixin,.ofwaters will be determined through extended tme tr als. after the proposesevaporation pond has been placed in operation. If d'4,rect plcacement, of waterc.into the propose,,,' evporation pond tend to cause excess-ive precipitation problemswith the spray systems, some of the alternatives ceirg considered are li'tedbe l ow,

1' Continued .eDiacement of waters to the east cell cf the large hLail in,,-fadility then decanted off to the proposed evaporation pond.

5' OFFICIAL DOCKET COPYAn Equal Opportunity Employer

Mr.Rao E.Yl.V eti

Page2' 2

2) Miin through* th brin svprtu pon thnp* nAspops-

Ktap razinuqh .:nd 9 C 'P~lrw(' :f~'

th larg talntalt hrfr redcn epg o1e0 va o lo

The extend.dus of spra' frm ndJ' conro -! als inrae h oalaon

from the aluva a quifer- tha We an:0-- x anange process vurll Kin ue

Homestake .~fr sk ht 0 Qn-a:ranar;e rr*;c'Psc be ,..,up-r F

Hamsak' ncra-v >cio pier- *h~ Qa p~:~ropose evap1 o~ra.t~ionppai

uon Inst-u cin, th Denry oil linri is the sipe~riov lie - h

oprto y oebr1 100 :oestake ir equest~s ani expeditiou.s review oftV

attahe design. - car -ron

ROESAK MINT\G rO AN

MaA D, 4.jle 6 ,

Raitoim etinAmn0 sj

-hAtaheV

XC7 Wrd Waf

DR.- G rv c-ý

DESIGN BRIEFEVAPORATION POND

HOMESTAKE MINING. COMPANY GRANTS OPERATION

GENERAL

This design brief describes the basis for the design of a newevaporation pond to be constructed on the site of Homestake MiningCompany's Grants Operation. Homestake is required by the USNRC tohave this evaporation pond in operation by November 1, 1990.Therefore, the construction of the pond must start no later thanearly July, 1990. This design brief is intended to providesufficient information to those regulatory agencies that haveauthority over the Grants Operation to enable them to perform anexpeditious review and approval of this design.

PERFORMANCE OBJECTIVES

The evaporation pond is intended to accomplish the followingperformance objectives:

1. Promote accelerated evaporation of liquids containingcontaminants associated with uranium ore milling

2. Provide a means of retention and temporary storage ofcontaminated liquids that would otherwise be discharged intothe ponds of the "active" or large tailing pile

3. Expedite the dewatering of the large tailing pile

DESIGN OBJECTIVES

The design was developed to satisfy the following objectives:

1. Create the storage capacity and surface area necessary to meetthe performance objectives

2. Prevent, or at least minimize, infiltration of contaminatedliquid to the underlying soils and ground water

3. Enhance evaporation by maximizing the effects of solar heating

4. Allow maximum flexibility in pond operations

5. Facilitate pond reclamation when its performance objectiveshave been accomplished and the pond is decommissioned

6. Enable regulatory approval to be obtained and construction tobe finished in time to start pond operations by November 1,1990

1

A rc 12

DESIGN CONSIDERATIONS

The design was guided and influenced not only by the foregoingobjectives but also by the following considerations:

1. The pond must be lined to meet ground water quality anddischarge requirements. A clay liner could satisfy thosestandards and requirements, but a synthetic liner would bequicker to place and would probably receive approval morereadily.

2. Placement of the evaporation pond on the old or "inactive"pile would:

a. keep the pond within the ground water quality point-of-compliance boundary;

b. preclude the necessity for additional ground watermonitoring;

c. allow reclamation of the pond to be included with thatof the old pile;

d. simplify site reclamation recontouring;

e. preserve potential borrow soil that would be lost if thepond were placed on alluvial soils.

3. The pond (inside) slopes need to be at a gradient sufficientlylow to allow adequate compaction of the liner base by heavycompaction equipment and also to allow mechanical placementof the liner on the inside slopes.

4. To avoid the necessity for double-handling of material orregrading at a later date, the pond outslopes should be shapedalong the old pile perimeter to approximately finalreclamation gradients, i.e. not steeper than 5H:lV.

5. The pond should be located to avoid placing the dikes orbottom of the pond over thick sections of wet slimes thatoccur in the south end of the pile.

6. All tailings should be kept within the perimeter defined bythe original tailing impoundment containment dikes.

7. To maximum extent possible, all evaporation spray systemcomponents (e.g. pipes, pumps, and spray nozzles) should bekept within the lined area of the pond.

8. The bottom of the pond should be kept at an elevation abovethat where the tailings could be reasonably expected to bewet.

2

9. Maximum reasonable use of solar heating should be made in thelayout of the pond slopes and the amount of pond surface thatis created in order to enhance evaporation.

DESIGN INPUT PARAMETERS

The input parameters that guided the details of the pond designwere:

1. Liquid volume - The only long-term sources of liquiddischarged to the pond will be the ground water from thecollection wells and the free water and pore water drainedfrom the large pile. The former has been determined byHomestake to be a maximum of 350 gpm, a rate that is likelyto decrease with time, especially after dewatering of thelarge pile starts. The amount of the free water and porewater drained from the large pile is undetermined at thistime; but it could be from 1000 to 1500 AF, assuming 20million tons in the pile, 75% of which is saturated andcontains about 20% drainable water content. Residual andwash-down liquids from the mill are relatively insignificant,and the discharge of these liquids is expected to be completewithin the very near future. A quantitative water balancecalculation is not supportable by the existing data, so anarbitrary decision was made to use one-half year of maximumcollection well pumping discharge as the basis for determiningthe pond capacity (282 AF).

2. Surface area - A water surface area of approximately 20 acreswas arbitrarily set as a reasonable and sufficient area ofwater surface to accommodate both the storage retentioncapacity needed in the pond and to provide passive(unenhanced) evaporation of 30 million gallons per year,assuming a lake evaporation rate of 55 inches per year.

3. Configuration -

a. Plan, shape and size: The shape of the pond was dictatedby the old pile shape. The size of the pond needs toprovide a water surface area of approximately 20 acres.

b. Pump station location: The pump station needs to belocated on the north dike of the pond to keep it as closeas possible to the source of electrical power.

c. Pond slopes: The inside pond slope gradient of 4H:lV wasselected to allow heavy compactors to work on theseslopes to prepare the liner base and to allow mechanicalequipment to operate on these slopes to place the linerfabric and liner membrane. A 1OH:lV gradient wasselected for the north (south-facing) pond slope to

3

provide more surface area exposed to sunlight to enhancesolar heating in the area closest to the primaryevaporation spray array.

d. Crest width: A crest width of 15 feet was selected assufficient to allow vehicular traffic to move safelyaround the perimeter of the pond. The crest width iswider at the pump station to accommodate the placementof pumps, electrical building, and space for servicecranes and trucks.

4. Soil properties -

a. In-place tailings: In-place tailings and old tailingcontainment dike soils were assigned a cohesion value of0 and a friction angle value of 29 degrees. These valueshad been determined previously and had been accepted bythe regulatory agencies for material properties oftailings in the active or large tailing pile. In-placetailings under the south pond dike were assigned acohesion value of 500 psf and a friction angle value of10 degrees to reflect their more clayey composition, i.e.the higher concentration -f slimes in these tailings.

b. Random fill: This material, consisting of mixed tailingsands and slimes, was assigned a cohesion value of 0 anda friction angle value of 30 degrees, reflecting a slightincrease in the friction angle to account for the effectsof mechanical compaction. Otherwise, the properties ofthese soils are identical to the properties of the in-place tailings on the large pile. Based on ModifiedProctor compaction tests performed on these materials(see attachment), the random fill was assigned a drydensity of 103 pcf, equal to 90% of maximum ModifiedProctor dry density.

c. Type A structural fill: This fill is identified as sandytailings exclusive of fines. It is assigned a drydensity of 108 pcf, equivalent to 95% of Modified Proctordry density. The cohesion and friction angle values forType A fill are 0 and 30 degrees, respectively.

d. Type B structural fill: This material, which consistsof mixed clay and sand alluvial soils, had beeninvestigated in 1987; and from those tests, the soil wasassigned a dry density of 95 pcf, comparable to 95% ofthe average Standard Proctor maximum dry density. Nocohesion or friction values were assigned to the Type Bstructural fill-because it will be used only as shallowfill on outslopes and, therefore, will have littleinfluence on the structural stability of the pond. Todetermine the saturated density of the soils described

4

above, it was assumed that each soil had a porosity ofapproximately 0.39 and a moist water content of 20%.

5. Liner properties -

a. Permeability: Equivalent to those available in mostsynthetic liners, approximately 10 cm/sec

b. pH resistance: Up to 10, the highest value of liquidsto be placed in the pond

c. Specific gravity: Greater than 1.0, to prevent floatingof the liner

d. Softening point: Greater than 1500 F, to resist thedeleterious effects of solar heating

e. Other properties: Sufficient to provide resistance tochemical deterioration and to puncture, tear and burst.Comparable to those properties in other widely-usedliners.

DESIGN SUMMARY

The evaporation pond design is characterized by the following:

I. Pond configuration - A four-sided polygon. The west, northand east sides are set by the location of the original oldpile dikes. The south side dike location is set by capacityand area requirements of the pond and by the approximate northlimit of the wet slimes of the old pile.

2. Base elevation - Set at 6583 to stay above the depth of theknown wet lenses of tailings in the old pile.

3. Dike height - 16.1 feet above pond base, to provide 282 AFstorage capacity and 2.0 feet freeboard.

4. Fill -

a. Random: Mixed tailings compacted to at least 103 pcf

b. Structural Type A: Sand tailings compacted to at least108 pcf

c. Structural Type B: Alluvial soils placed on outslopesat not less than 95 pcf

5. Base preparation - The surface of the structural fill willbe rolled to create a smooth surface that will support 300 psiwith not more than one-half inch indentation, to protect theliner from stress concentrations.

5

6. Pump station - The pump station will consist of three concretemat foundations for up to three pumps to be installed byHomestake in the future, as needed. The pump station areawill be covered by the liner constructed to the samespecification as that underlying the pond and will surroundedby a concrete rim not less than 0.5 feet above surroundingelevation to contain any liquids that might leak from thepumps and to drain them back to the pond.

7. Liner - The liner will be 50 mil polyester fabric covered byat least 90 mil of Deery #6 membrane sprayed on to create acontinuous, seamless liner.

8. Spray system - Not part of the pond design. The spray systemis an operational option that Homestake will exercise to theextent necessary to evaporate liquids at a rate which willkeep the pond water level below the design maximum of 6597.1,providing not less than two feet of freeboard at all times.

9. Water pipeline - Not part of the design. The pipeline willbe installed by Homestake and will include a double pipe(inner transport pipe within outer protective pipe) in thatsection that crosses the outslope and crest of the evaporationpond.

10. Structural stability - Stability analyses were performed onSection B-B! and Section E-E' (see Drawings EP1 to EP3) todetermine the factors of safety under static and pseudostaticload conditions. Those factors of safety are, respectively,1.77 and 1.09 for B-B' and 1.72 and 1.02 for Section E-E'.Section B-B' is a section through the midpoint of the southdike and is the section with the weakest foundationconditions. Section E-E' is along the midpoint of the northdike at the pump station and represents the section with thelargest crest width and the steepest outslope.

Attached to this Design Brief are specifications HMC/REC.EP1 (pondconstruction) and HMC/REC.EP2 (pond liner) and Drawings EPl throughEP7. Also attached are the records of soil tests on which physicalproperties of tailings and alluvial soils are based.

6

SPECIFICATION

FOR

CONSTRUCTION OF EVAPORATION PONDAND APPURTENANT FACILITIES

HOMESTAKE MINING COMPANYGRANTS OPERATION

NEW MEXICO

NO. HMC/REC.EP1Revision 0

June 4, 1990

Prepared by:AK GeoConsult, Inc.

~~1

>WkJ

Spec. HMC/REC.EP1, Revision 0

PART 1 - GENERAL

1.01 Project Description

Homestake Mining Company will construct an evaporation pond at itsGrants, New Mexico operation as part of its reclamation plan forthe uranium mill and tailing piles on that site. The evaporationpond will have a storage capacity of approximately 282 acre-feetfor temporary retention and evaporation of contaminated groundwater and liquid tailing solutions. The pond will be constructedon and within the "inactive" tailing impoundment, the smaller ofthe two tailing impoundments, that has not received mill tailingssince the early 1960's. The tailings will be excavated and placedas compacted fill to form the pond and the dikes enclosing thepond. The pond will be lined with a two-part liner of polyesterfabric and spray-on membrane that will cover the pond bottom,inside (pond) slopes, and pump station. An evaporative spraysystem will be used as needed to enhance evaporation and willconsist of one to three separate arrays. Each array will have apump, distribution pipes and spray nozzles. All pumps will belocated at a pump station on north dike.

1.02 Included Work

The activities required for construction of the evaporation pondhave been grouped into several separate work packages or contracts.The work covered in this specification is required to construct thepond structure and the pump station foundations and to preparesurfaces for the liner. The Include Work consists of:

o Site preparation: Clearing vegetation, foreign materialsand rock from the area to be excavated or filled

o Excavation: Excavation of tailings and soil whereexisting ground surface is above design grades or whereexisting materials have unacceptable properties, andexcavation of native soil from adjacent borrow areas

o Fill: Placement and compaction of excavated tailings andsoil in locations where existing surfaces are belowdesign grades or existing materials must be replaced

0 Liner base preparation: Final grading and rolling of

surfaces to be covered by liner

o Pump station construction: Excavation, subgradecompaction; forming, reinforcing mat fabrication, andconcrete placement for three mat foundations for pumpsand the rim around the pump station; and electricalconduit installation.

o Gravel placement on roadways: Placement and compactionof minus 2.0 inch gravel on designated roadways leadingonto the pond dikes


1.03 Related Work

O Liner Installation - Liner materials and installationwill be provided by a separate contractor.

o Installation of Water Pipeline, Pumps and EvaporationSystem - All materials, equipment and labor required forinstalling the water pipeline(s), pumps, and evaporationspray system (including piping and electrical service)will be provided by HMC or another contractor.

1.04 Responsibilities

a) Homestake MininQ Company (HMC): HMC, the "Owner", willevaluate bids and award all contracts for the IncludedWork (Section 1.02) and Related Work (Section 1.03), willprovide controlled access to the work site, will makeavailable construction water at a location on the millproperty and will approve and make payment for workperformed under this specification. The Owner willperform surveys to verify finished lines and grades andexcavation and fill quantities.

b) AK GeoConsult, Inc. (AKG): AKG, the "Engineer," willreview or inspect and advise the Owner on the acceptanceof the Included Work. The Engineer will implementquality control measures for the Owner that will includefield density testing, laboratory testing of concrete,and testing of the liner.

c) Contractor (to be determined) shall provide allequipment, materials, labor and supplies and perform allwork necessary to accomplish the Included Work.Contractor shall be responsible for the safety of its jobsite and of all personnel and equipment which it employson the job site. Contractor shall be responsible forcontrolling lines and grades of excavation, fill, andfinished earth and concrete surfaces.

1.05 Definitions

Compactors, heavy: Self-propelled or towed compaction machineryincluding rubber-tired rollers, tamping foot (sheep's foot)rollers, and smooth drum vibrating compactors weighing inexcess of 5000 lbs. and controlled by a mounted operator.

Compactors, light: Vibrating or tamping compactors weighing lessthan 5000 lbs. and controlled by a walk-behind operator.

Disposal area: The area on the south end of the inactive tailingpile designated for disposal of vegetation and foreignmaterial.

2


Fines: Mineral particles (soil or tailings) passing the #200 U.S.Standard sieve; i.e. smaller than 0.075 mm grain size.

Foreign material: Any solid material that is not either naturalsoil or tailings. Includes wood, iron and steel, plastic,rubber, glass, ceramic and concrete.

Inactive tailing impoundment, inactive tailing pile: Thepentagonal-shaped earthfill structure located on HMC Grantsproperty southwest of the mill and south of the active tailingpile. The evaporation pond will be constructed on the northhalf of the inactive tailing pile.

Job site: The location of the inactive tailing pile as well as allaccess routes, borrow areas, equipment laydown locations andstorage areas on HMC property used in the Included Work.

Liner: A man-made barrier with very low permeability that blocksliquid flow from the evaporation pond, composed of natural orsynthetic materials

Native soil, natural soil: Naturally-occurring alluvial orresidual soils existing below and at ground surface around thejob site; consisting of gravel, sand, silt and clay materials.

Sand: Mineral particles with grain sizes between #200 and #4 sieve(0.075 mm to about 5 mm).

Slimes: Tailings containing more than 50% silt and clay sizes(minus #200 sieve) classi±fied as CL, CH, ML, or MH soil.

Soil classification: Soil descriptions based on grain sizedistribution and plasticity in accordance with the UnifiedSoil Classification System (USCS). Expected soilclassifications are:

SP - poorly-graded sand with less than 5% finesSM - silty sand composed of 12-50% silt fines and 50% or more

sandSC - clayey sand composed of 12-50% clay fines and 50% or more

sandSP-SM - sand with 5-12% silty finesML - more than 50% fines that classify as silt, according to

reference b, and liquid limit less than 50MH - same as ML except liquid limit 50 or moreCL - more than 50% fines that classify as clay, according to

reference b, and liquid limit less than 50CH - same as CL except liquid limit 50 or more

Tailings: Solid byproduct of uranium ore milling, consisting ofparticles of primarily silicate minerals with less than 1%radioactive elements (mostly uranium and radium). Particlesizes range from clay (less than 0.002 mm) to medium sand(less than #40 sieve).

3


1.06 References

a) ASTM D 1557-78 "Standard Test Methods for Moisture-DensityRealtions of Soils and Soil-Aggregrate Mixtures Using 10-lb(4.54-kg) Rammer and 18-in. (457-mm) Drop", Vol 04.08, 1988Annual Book of ASTM Standards

b) Casagrande, A., 1948, "Classification and Identification ofSoils," Transactions of the American Society of CivilEngineers, Vol. 113, P. 901.

1.07 List of Drawings

The following drawings are incorporated into this specification byreference:

#EP1 Plan of Evaporation Pond

#EP2 Sections of Pond Dike

#EP3 Sections of North Dike of Evaporation Pond

#EP4 Pump Station

#EP5 Details of Liner

#EP6 Survey Points for Line and Grade Control

#EP7 Pump Foundation Details

4


PART 2 - EXECUTION

The Contractor shall perform the following work:

2.01 Site Preparation

Remove vegetation and foreign material from the areas of excavationand fill, as shown on Drawing EP1, and dispose of it in thedesignated disposal area. Any pieces of foreign material that aretoo small to be individually handled by earthmoving equipment shallbe removed by hand or excavated with the surrounding tailings andplaced in the disposal area. HMC and the Engineer, at theirdiscretion, shall permit some foreign material to be left in placeif it will subsequently be covered by at least 1.0 foot ofcompacted fill and if the subject material is small enough in sizeand quantity that its presence will not significantly affectcompaction or other construction activities or materials.

2.02 Excavation

After site preparation has been completed, excavate tailings andnatural soils to reduce ground surface to the design grades shownon Drawings EPl, EP2, EP3 and EP4. Excavated tailing sand andnatural soils that are free of vegetation or foreign material shallbe used as fill, as described in Section 2.03. Slimes that arejudged by HMC or the Engineer to be unacceptable for fill shall bedisposed in the designated area on the south end of the inactivetailing pile. Slimes that are accepted by HMC or the Engineer forinclusion in the fill shall be mixed with tailing sand duringexcavation or at the fill location.

The volume of tailing excavation is expected to exceed the volumeof fill required to construct the pond and dikes. If so directedby HMC, excess excavated tailings shall be placed first in thedesignated test area south of the evaporation pond, as shown onDrawing EPI. Any volume of excavated tailings that exceeds thefill requirements of evaporation pond construction and the testarea shall be disposed in the same location as that used fordisposal of unacceptable slimes or in locations along the southside of the tailing impoundment designated by HMC.

2.03 Fill

Random Fill

Place and compact random fill in locations of the pond dikes asshown on the drawings and as directed by HMC. All fill used toconstruct the pond dikes (including crest, inside slope, and thoseportions of the outslope not contructed over the original tailingscontainment dikes), up to elevations 1.0 foot below final designgrades, is random fill. Random fill may include sand tailingsclassified as SP, SP-SM, SM, or SC; natural soil classified as CL,CH, ML or MH; and slimes classified as CH, CL, or ML excavated fromthe tailing pile and acceptable to HMC or the Engineer. It shallbe placed in lifts of not more than eight inches loose thickness

5


and at gradients from horizontal to not more than 10%. Each liftshall be moisture-conditioned, mixed, and compacted to achieve in-place dry density of not less than 103 pounds per cubic foot (pcf).In lifts that contain slimes, the slimes shall be mixed with sandtailings to create a uniform sand-slime mixture without visibleclumps or concentrations of slimes. Adequacy of this mixing shallbe determined by HMC, the Engineer, or its designatedrepresentative.

No fill shall be placed on any surface that is saturated, frozen,or holding free water. No fill shall be placed that contains iceor frozen soil. After any precipitation that causes ponding ofwater on the fill surface, the water shall be drained and thesurface shall be allowed to dry, then scarified and recompactedbefore the next lift is placed.

Throughout fill construction the fill surface shall be maintainedto facilitate runoff and prevent ponding. Within the pond area(inside the perimeter defined by the dike crest) ponded water shallbe removed by pumping to the south end of the inactive tailingpile, south of the south dike of the evaporation pond and withinthe limits of the pile containment dike.

HMC, the Engineer, or its authorized testing service will performfield tests to determine in-place densities and moisture contentsof the fill. A minimum of one in-place density test for each 5000yards of random fill will be conducted. If any portion of the fillfails to meet the required density, that portion shall berecompacted until it achieves the minimum required density.

Structural Fill

Place and compact structural fill at selected locations as follows:

Type A: All fill placed within 1.0 feet of final design grade onthe dike crest and inside slopes, the outslope of the south dike,and the pond bottom shall be Type A structural fill. Type Astructural fill shall consist of sand tailings with USCSclassification of SP, SP-SM, SC or SM and shall be free of slimes.

Type B: Structural fill placed in the dike outslopes above theoriginal tailing containment dike, and in the top 1.0 foot of alloutslopes except on the south dike, shall be Type B structuralfill. Type B structural fill shall consist of natural soilclassified as SP, SP-SM, SM, SC, ML, CL, or CH that occurs atshallow depths around the west, south and east sides of theinactive tailing pile. The Contractor shall develop borrow pitsfor Type B structural fill at natural soil locations convenient tothe work and acceptable to HMC.

Structural fill shall be placed in lifts of not more than eightinches loose thickness when it is to be compacted by heavycompactors. Lifts to be compacted by light compactors shall notexceed four inches loose thickness. Each lift of Type A fill shallbe compacted to not less than 108 pcf dry density, and each lift

6


of Type B fill shall be compacted to not less than 95 pcf drydensity.

No fill shall be placed on any surface that is saturated, frozen,or holding free water. No fill shall be placed that contains iceor frozen soil. After any precipitation that causes ponding ofwater on the fill surface, the water shall be drained and thesurface shall be allowed to dry, then scarified and recompactedbefore the next lift is placed.

Throughout fill construction the fill surface shall be maintainedto facilitate runoff and prevent ponding. Within the pond area(inside the perimeter defined by the dike crest) ponded water shallbe removed by pumping to the south end of the inactive tailingpile, south of the south dike of the evaporation pond and withinthe limits of the pile containment dike.

HMC, the Engineer, or its authorized testing service will performfield tests to determine in-place densities of the fill. A minimumof one in-place density test for each 2000 yards of structural fillwill be conducted. If any portion of the fill fails to meet therequired density, that portion shall be recompacted until itachieves the minimum required density.

Finished fill surfaces shall meet the following minimum acceptancecriteria for line and grade:

Pond corners at crest centerline - specified New Mexico Gridcoordinates +/- 1.0 foot.

Pond dike alignment - centerline not more than 1.0 footdeparture from straight line connecting crest cornersestablished as above.

Crest elevation - elevation 6599.1 along the dike centerline,6599.3 along inboard (pond side) edge, 6598.9 along outboardedge; maximum variance +/- 0.1 foot.

Pond bottom - Elevation 6583.0 +/-0.25 feet

Pond slope (inside slope) gradient - Specified gradient +/-4%

Outslope (outside slope) gradient - Not greater than 0.2 norless than .17 on all nominal 5H:lV slopes, +/- 5% elsewhere.

Pump station surface - North edge elevation between 6600.2 and6599.5, sloped toward pond at 0.03 to 0.05 gradient.

2.04 Liner Base Preparation

Prepare all surfaces of the inside slope, pond bottom, and pumpstation for installation of the pond liner. Preparation shallconsist of rolling the final-grade surface with smooth drum orrubber wheel rollers until:

7


1) the surfaces experience indentations less than 1/2 inchdeep when crossed by rubber-tire equipment exertingground pressures of up to 300 psi,

2) irregularities in the surface (surface roughness) areless than 0.1 (ratio of height to least-width of anyprotrusion in the surface is less than 1 to 10), and

3) no foreign materials are visible on the surface.

The prepared liner base shall be tested for the three foregoingpreparation criteria by HMC or the Engineer at not fewer than 10locations on the pond bottom and 6 locations on the inside slopes.

2.05 Pump Station Construction

Pump Foundations

Construct three reinforced concrete mat (spread) foundations forthe evaporation spray system pumps at the pump station on the northdike (Drawings EP4 and EP7). Each foundation shall be 8 feet long,6 feet wide, and 2 feet thick, with a mat of #4 steel reinforcingbar, ASTM A 615, Grade 60; and 8 anchor bolts, as shown on DrawingEP7. The bottom elevation of each foundation shall be 6597.6 +/-

0.2 feet, or 18 inches below the design elevation of the crestcenterline. The tailing surface under each foundation shall becompacted by hand-operated tamper to create a smooth, horizontalbearing surface.

Formwork shall consist of clean lumber, plywood, or both; andremoveable metal form ties. Lines, levels and measurements on theformworks shall be verified in the presence of HMC or the Engineer.

Concrete used for pump foundations shall be mixed in accordancewith ASTM C94 and shall contain Type 1 Portland cement per ASTMC150 and aggregates conforming to ASTM C33 that are free of spall-causing deleterious materials. Water used in the mix shall bepotable. The W/C ratio of the concrete shall be 0.44 maximum.Slump at point of placement shall be 1-3 inches.

The concrete of each foundation shall be placed in a continuouspour and pneumatically vibrated per ACI 309 after each lift of notmore than 12 inches. The top surface shall be worked to a floatfinish deviating not more than 1/4 inch from a planar surface atany point on the surface. The finished pour shall be kept moistand covered with a moisture-retaining cover complying with ASTM C171 for one week. Remove forms at least 24 hours after the pour.

The finished foundations shall satisfy the following requirements:

a) concrete compressive strength at 28 days: 4000 psib) maximum surface slope, along 8-foot length: 0.25 inchc) maximum surface slope, across 6-foot width: 0.25 inch

8


Electrical Conduit Installation

Install electrical conduits from the north side of each pumpfoundation to the location north of the pump station shown onDrawing EP4. Three conduits (two each 2 1/2-inch and conduits oneeach 1-inch conduit) shall be installed within 1.0 feet of thenorth edge of each foundation, extending vertically from at least1.0 feet above final maximum station grade (elevation 6599.6) toat least 3.0 feet below design crest grade (not higher thanelevation 6596.1). At the bottom end of each vertical section,each conduit shall have a 90 degree elbow connecting to a straighthorizontal section.

The conduits may be installed at the time of fill construction orin trenches excavated after fill construction. If the Contractorelects to install the conduits after pump foundation construction,he shall take precautions necessary to prevent disturbance of thefoundations or their subgrades. If trenches are dug for conduitinstallation, the material excavated from the trenches shall beused as backfill and compacted to structural fill density (section2.03) using light compactors.

Conduit materials shall be supplied by HMC.

Pump Station Rim

Construct a rim around the west, north, and east side of the pumpstation at the locations shown on Drawing EP4. The rim shallextend at least 0.5 feet above the adjacent final grade of the pumpstation and shall be not more than 2.0 feet wide at its base. Therim shall be either cast-in-place or precast concrete segments andshall be semicylindrical in shape, with the curved surface facingupward. The concrete shall meet the same requirements as thosespecified for the pump foundation concrete except that the minimum28-day compressive strength shall be 2000 psi. The Contractor maypropose alternative methods of construction for HMC's approval.

Pump Station Final Grade

After installation of conduits and construction of pump foundationsand the pump station rim, place and compact Type A structural fillin the pump station area to establish the gradients shown onDrawing EP4. The fill shall be placed and compacted to form auniform north-to-south slope of 3% to 5% from the north side of thepump station to the top of the north inside slope of the pond.Compaction shall be achieved by light compactors.

9


2.06 Roadway Gravel Placement

Place well-graded gravel (USCS soil classification GW) with maximumsize of 2.0 inches on the roadways shown on Drawing EPI. Thegravel cover on each roadway shall extend from the bottom to thetop of the 5H:lV outslope along a road width not less than 15 feetnor more than 18 feet. Final gravel cover thickness shall be notless than 2 inches nor more than 4 inches. The gravel shall bespread by dozer or grader and compacted by successive passes ofthis equipment to form a surface that supports passage of equipmentexerting ground pressures up to 300 psi.

10


PART 3 - QUALITY CONTROL

The Contractor shall take all measures necessary to achieve allrequirements of Part 2 of this specification. These measures shallinclude, as a minimum, the following:

3.01 Supervision

During all times that the Contractor's equipment or personnel areperforming Included Work on the job site, a Contractor supervisorshall be present to direct the work. The supervisor shall haveexperience, satisfactory to HMC, in the type of work beingexecuted. The supervisor shall have on-hand at all times a copyof the current revision of this specification and the drawingsrelevant to the work. The supervisor shall have the authority tomake decisions for the Contractor in all matters related to parts2 and 3 of this specification.

3.02 Line and Grade Control

The Contractor shall perform land surveying to determine that thespecified lines and grades have been achieved in accordance withthe limits established in this specification and Drawing EP6.Ground control for surveys shall be based on established benchmarksand other control points on the mill property. Crest alignmentsand slope gradients shall be surveyed as often as necessary tocontrol excavation and fill placement.

When the Contractor reports to HMC that all Included Work has beencompleted, HMC will perform an acceptance survey to determine ifline and grade requirements h5vŽ been satisfied. HMC will surveythe crest alignments and L--1 ;ions and the slope gradients atintervals of not less than 200 feet along the dike at locationsselected by HMC. The pond bottom elevations shall be measured ona 200-foot square grid starting at a point to be selected by HMC.The pump station elevations and gradients shall be measured at fournorth-south cross-sections selected by HMC. The pond cornercoordinates will also be surveyed at this time.

3.03 Field and Laboratory Testing of Fill

Testing of fill materials and in-place density and moisture willbe performed by a qualified materials testing service contractedby HMC. Field density on compacted fill will be performed by theSand Cone method, ASTM D 1556, as the primary method. If reliablecorrelations and calibrations can be established in the first 10density tests between nuclear methods for density (ASTM D 2922) andmoisture (ASTM D 3017) and the Sand Cone method, the nuclearmethods will become the primary method and the Sand Cone methodwill be used thereafter on 10% of all subsequent tests as aduplicate test for confirmation of nuclear testing results.

11


3.04 Liner Base Preparation

The Contractor shall notify HMC when liner base preparation hasbeen completed. At that time HMC will conduct an inspection of theprepared surface with the Contractor and the liner-installationcontractor. The inspection shall include visual examination of thesurface and both video and photographic recording of the conditionof the base, including traverses by a vehicle that exerts groundpressures of approximately 300 psi. As a minimum, the traversesshall follow a square grid pattern not larger than 200 feet. Tireindentation depths will be measured by HMC at locations that itdeems appropriate, but not fewer than 20 measurements will be madeover the pond bottom and 10 measurements will be made on the pondslopes.

3.05 Pump Foundations

Pump foundation construction will be inspected by HMC at severalstages. Initially, the compaction of the foundation base soil willbe observed and, if judged necessary by HMC, tested for in-placedensity before forms are constructed. The specified elevations andmaximum slopes of the forms shall be measured by the Contractor andwitnessed by HMC prior to placement of rebar and concrete. Threetest cylinders of concrete, one from each foundation, shall beobtained for strength testing by the materials testing contractor.The foundations will not be accepted until the minimum acceptancecriteria, described in Part 2, have been achieved.

12


PART 4 - DOCUMENTATION

4.01 - Documentation by Contractor

The Contractor shall record and report, in a format acceptable toHMC, the following information:

Daily journal containing list of equipment used, hours worked,reimbursable materials consumed or used, and labor hours bywage category. The journal will also record Included Worktasks started, completed, and in progress and the units ofwork accomplished (e.g., volume of excavation and fill, areaof final grading). Submit a copy to HMC by the start of thenext working day.

Daily Work Summary listing all pay items and quantities.Submit by the start of the next working day.

Survey notes for line and grade control (verbally reportresults immediately, and submit copy to HMC within 24 hours)

Written notifications to HMC of unexpected conditions,conditions that prevent conformance with specifications,disputes over acceptance of Contractor's work. Verballynotify HMC immediately upon discovery or identification,submit in writing within 24 hours.

4.02 - Documentation by HMC

HMC will create and maintain the following documentation thatrelates to the Included Work:

Field inspection notes of Contractor's performance, workaccomplished, and variances from the specifications observedby HMC.

Records of all field and laboratory tests performed by HMC andits testing service.

Photographic and video tape records of the Included Work.

Chronological record of notifications to the Contractor ofvariances from specifications, unacceptable work performance,discrepancies in payment quantities claimed by the Contractor,and all related resolutions thereto.

Survey notes and calculations of the acceptance survey(section 3.02)

As-built drawings of completed work.

13


PART 5 - ACCEPTANCE

HMC shall have sole discretion to accept in part or in full, or toreject in part or in full, the Contractor's work. Acceptance orrejection will be based on HMC's visual inspections (includingthose of its Engineer and testing service), quality control datarequired under Part 3, and documentation required under Part 4.

Upon identification of unacceptable work, HMC will notify theContractor of the deficiency. The notification will include thelocation, extent, and description of the unacceptable work. Beforeproceeding with additional work at that location the Contractorshall correct the deficiency by bringing the work into compliancewith specifications and drawings to the satisfaction of HMC. Allwork and materials required for such corrective actions shall beat the expense of the Contractor.

14


PART 6 - SCHEDULE

Complete the Included Work within 75 calendar days according to thefollowing schedule:

Notice to Proceed Day 0Complete mobilization, commence work task 2.01 Day 15Complete task 2.01 Day 30Complete tasks 2.02 and 2.03 Day 60Complete tasks 2.04, 2.05, and 2.06 Day 75

Weather conditions that prevent work on a specific task for anentire work day shall be accommodated by a day-for-day extensionin the schedule of that and other directly affected tasks.

15

SPECIFICATION

FOR

CONSTRUCTION OF EVAPORATION POND LINER

HOMESTAKE MINING COMPANYGRANTS OPERATION

NEW MEXICO

NO. HMC/REC.EP2Revision 0

June 7, 1990

Prepared by:AK GeoConsult, Inc.


PART 1 - GENERAL

1.01 Project Description

Homestake Mining Company will construct an evaporation pond at itsGrants, New Mexico operation as part of its reclamation plan forthe uranium mill and tailings piles on that site. The pond andpond liner have a design life of 15 years. The evaporation pondwill have a storage capacity of approximately 282 acre-feet fortemporary retention and evaporation of contaminated ground waterand liquid tailing solutions. The pond will be constructed on andwithin the "inactive" tailing impoundment, the smaller of the twotailing impoundments, that has not received mill tailings since theearly 1960's. The tailings will be excavated and placed ascompacted fill to form the pond and the dikes enclosing the pond.The pond will be lined with a two-part liner of polyester fabricand spray-on membrane that will cover the pond bottom, inside(pond) slopes, and pump station. An evaporative spray system willbe used as needed to enhance evaporation and will consist of oneto three separate arrays. Each array will have a pump,distribution pipes and spray nozzles. All pumps will be locatedat a pump station on north dike.

1.02 Included Work

The activities required for construction of the evaporation pondhave been grouped into several separate work packages or contracts.The work covered in this specification is required to supply andinstall the pond liner. The Include Work consists of:

o Supply of all liner materials: Supply all materialsrequired to install and test the liner.

o Installation: Install the liner and the anchorage neededto keep the liner in place and functioning as requiredfor the design life of the pond.

o Testing: Perform all tests necessary to document thatthe liner meets the design requirements.

1.03 Related Work

O Pond Construction - Earthwork and concrete work toconstruct the pond, enclosing dikes, pump station, androadways will be performed by a separate contractor.

O Installation of Pumps and Evaporation - System - Allequipment and labor required for installing theevaporation spray system, including procurement andinstallation of pumps, piping, and electrical servicewill be provided by HMC or another contractor.

1


1.04 Responsibilities

a) Homestake Mining Company (HMC): HMC, the "Owner", willevaluate bids and award all contracts for the IncludedWork (Section 1.02) and Related Work (Section 1.03), willprovide controlled access to the work site, will makeavailable construction water at a location on the millproperty and will approve and make payment for workperformed under this specification.

b) AK GeoConsult, Inc. (AKG): AKG, the "Engineer," willreview or inspect and advise the Owner on the acceptanceof the Included Work, including installation and testingof the liner.

c) Contractor (to be determined) shall provide allequipment, materials, labor and supplies and perform allwork necessary to accomplish the Included Work.Contractor shall be responsible for the safety of its jobsite and of all personnel and equipment which it employson the job site.

1.05 Definitions

Compactors, heavy: Self-propelled or towed compaction machineryincluding rubber-tired rollers, tamping foot (sheep's foot)rollers, and smooth drum vibrating compactors weighing inexcess of 5000 lbs. and controlled by a mounted operator.

Compactors, light: Vibrating or tamping compactors weighing lessthan 5000 lbs. and controlled by a walk-behind operator.

Disposal area: The area on the south end of the inactive tailingpile designated by HMC for disposal of vegetation and foreignmaterial.

Fines: Mineral particles (soil or tailings) passing the #200 U.S.Standard sieve; i.e. smaller than 0.075 mm grain size.

Foreign material: Any solid material that is not either naturalsoil or tailings. Includes wood, iron and steel, plastic,rubber, glass, ceramic and concrete.

Inactive tailing impoundment, inactive tailing pile: Thepentagonal-shaped earthfill structure located on HMC Grantsproperty southwest of the mill and south of the active tailingpile. The evaporation pond will be constructed on the northhalf of the inactive tailing pile.

Job site: The location of the inactive tailing pile as well as allaccess routes, borrow areas, equipment laydown locations and

2


storage areas on HMC property used in the Included Work.

Liner: A man-made barrier with very low permeability that blocksliquid flow from the evaporation pond, composed of natural orsynthetic materials.

Native soil, natural soil: Naturally-occurring alluvial orresidual soils existing below and at ground surface around thejob site; consisting of gravel, sand, silt and clay materials.

Sand: Mineral particles with grain sizes between #200 and #4 sieve(0.075 mm to about 5 mm).

Slimes: Tailings containing more than 50% silt and clay sizes(minus #200 sieve) classified as CL, CH, ML, or MH soil.

Soil classification: Soil descriptions based on grain sizedistribution and plasticity in accordance with the UnifiedSoil Classification System (USCS). Expected soilclassifications are:

SP - poorly-graded sand with less than 5% finesSM - silty sand composed of 12-50% silt fines and 50% or more

sandSC - clayey sand composed of 12-50% clay fines and 50% or more

sandSP-SM - sand with 5-12% silty finesML - more than 50% fines that classify as silt, according to

reference b, and liquid limit less than 50MH - same as ML except liquid limit 50 or moreCL - more than 50% fines that classify as clay, according to

reference b, and liquid limit less than 50CH - same as CL except liquid limit 50 or more

Tailings: Solid byproduct of uranium ore milling, consisting ofparticles of primarily silicate minerals with less than 1%radioactive elements (mostly uranium and radium). Particlesizes range from clay (less than 0.002 mm) to medium sand(less than #40 sieve).

1.06 References

Applicable standards of the American Society for Testing andMaterials (ASTM) including, but not limited to:

Vol. 07.01 Textiles - Yarns, Fabrics, and General Test MethodsVol. 09.01 Rubber, Natural and SyntheticVol. 09.02 Rubber Products, IndustrialVol. 14.02 General Test Methods, Nonmetal

3


1.07 List of Drawings

The following drawings are incorporated into this specification byreference:

#EPl Plan of Evaporation Pond

#EP2 Sections of Pond Dike

#EP3 Sections of North Dike of Evaporation Pond

#EP4 Pump Station

#EP5 Details of Liner

4


PART 2 - EXECUTION

The Contractor shall perform the following work:

2.01 Furnish Liner Materials

The Contractor shall fabricate or procure, inspect at the point oforigin, and transport to the job site all materials required toinstall the liner. The liner shall have the following properties:

Composition

The liner shall be a composite of fabric and membrane.

Fabric - Trevira spunbond 100% continuous-filament polyester,minimum grade 1112, or other material with equal or betterproperties, as approved by HMC.

Membrane - Deery #6 thermoplastic mixture of asphalts, oils,resins, antioxidants, and synthetic polymers.

Properties

The liner materials shall have the following minimum properties:

Fabric

Thickness - 50 mils per ASTM D-1777Fabric Weight - 3.4 oz./sq yd per ASTM D-3776Grab Strength - 80 lbs per ASTM D-4632Grab Elongation - 60 % per ASTM D-4632Trapezoid Tear Strength - 30 lbs per ASTM D-4533Puncture Resistance - 35 lbs per ASTM D-3787Mullen Burst Strength - 160 psi per ASTM D-3786

Membrane

Thickness - 90 milsSpecific Gravity - 1.1 maximum per ASTM D-71Softening Point - 180 degrees F per ASTM D-2398Penetration - 90 maximum at 77 degrees F, 120 maximum at

115 degrees F per ASTM D-1191Elongation - 300% per ASTM D-3407 (sample size)Flexibility - Excellent per ASTM D-3407 (sample size)Resilience - 30 (60 sec.) per ASTM D-3407

Permeability - 10- 1 1 cm/sec under 20 ft. of hydrostatichead

5


Chemical Reactivity - chemical stability and resistancesufficient to meet all material and performancerequirements for 15 years while in direct contactwith:

Sodium - up to 20,000 mg/lBicarbonate - up to 5,000 mg/lChloride - up to 4,500 mg/lSulfate - up to 27,000 mg/lTDS - 61,000pH - up to 10.0

2.02 Installation

Install the liner over the pond bottom, inside slopes, and pumpstation as shown on Drawings EPI, EP2, EP3, EP4, and EP5. Anchorthe liner by keying it into the fill on the crest of the pond dike,as shown on Drawings EP4 and EP5.

Surface Preparation

The liner shall be installed on surfaces that have been preparedby another contractor (earthwork contractor). That contractor isrequired to place and compact 1.0 feet of sand tailings fill belowall surfaces to receive the liner. That fill is to be compactedby the earthwork contractor to at least 108 pcf drydensity, then rolled to create a firm surface free of foreignmaterial and able to support rubber-tire ground pressures of up to300 psi with resulting indentations not to exceed 1/2 inch depthand with surface irregularities (surface roughness) less than 0.1(ratio of height to least-width of any protrusion in the surfaceless than 1 to 10). If these criteria for surface preparation arenot acceptable to the Contractor, it shall so state in its bidsubmittal and propose its own criteria. If the Contractor'sproposed criteria are accepted by HMC, this specification and theearthwork specifications in Spec. HMC/REC.EPI shall be revisedaccordingly.

The Contractor shall inspect the prepared surface prior to fabricplacement to determine if it is acceptable according to thecriteria for installation of the liner. If the Contractor findsany portion of the surface unacceptable, the conditions of thatsurface shall be documented by photography and measurements by theContractor in the presence of HMC and the earthwork contractor.If HMC agrees that the subject surface does not satisfy the surfacepreparation criteria, the earthwork contractor shall rework thatsurface until the criteria are satisfied.

The prepared surface will be tested against the preparationcriteria by HMC or the Engineer at not fewer than 10 locations onthe pond bottom and 6 locations on the inside slopes.

6


Notwithstanding the foregoing actions, if the Contractor is notsatisfied with the prepared surface after the preparation criteriahas been met, the Contractor may perform additional work to preparethe surface at its own expense. The Contractor shall beresponsible for repairing at its own cost any damage to theprepared surface caused by its own actions.

Fabric Installation

Install the liner fabric in accordance with the proceduresspecified by the fabric manufacturer. These procedures will besubmitted in writing with the Contractor's bid and shall beaccepted by HMC before installation begins. If the manufacturerdoes not provide written installation procedures to the Contractor,the Contractor shall prepare its own procedures for acceptance byHMC.

The installation procedures shall include, as a minimum, thefollowing:

Method of placement on the prepared surface

Minimum overlap of adjacent rolls or strips

Limiting weather and moisture conditions for installation

Membrane Installation

Install the membrane over the entire surface area covered by thefabric as well as over at least 6 inches of those concrete, steel,and plastic surfaces that contact or penetrate the liner. Themembrane shall be applied by power spray at temperatures not toexceed 420 degrees F. The spray nozzles shall be hand-held forapplication of two or more coats of membrane in the pump stationarea, but shall be mounted on spreader bar attached to a tank truckfor general application over the pond surfaces.

At lines of contact between the liner fabric and other materials(concrete, steel, and plastic) in the pump station area, additionalcoats of membrane shall be applied to create a thickened membraneseal between the two adjacent materials that is at least 1/2 inchthick at the point of contact and has a surface that makes a smoothcurve between the adjacent surfaces, as illustrated in Drawing EP4.

Any 10,000 square-foot section of liner in the pond or 100 square-foot section of liner in the pump station that has less than therequired thickness of membrane, as determined in section 3.02below, shall receive additional applications of membrane untilsubsequent measurements determine that the required thickness hasbeen applied.

7


Liner Anchorage

Construct a continuous liner anchor in the dike crest around theentire pond. The liner anchor shall be constructed by:

1) Excavation of a trench in the crest not less than 2.0feet deep, with the pondward edge between 1.0 and 4.0feet from the top of the pond slope. The shape and otherdimensions of the trench may vary, depending on theequipment used to excavate the trench. Except for thatpart of the trench around the pump station, excavationby motorized grader is an acceptable method and wouldproduce a trench shape like that shown on Drawing EP5.

2) Lay each roll of liner fabric so that it runscontinuously from the bottom of the pond slope onto thecrest and across the sides and bottom of the anchortrench.

3) Place and compact not more than 1.0 feet of sand tailingsover the liner fabric in the bottom half of the anchortrench.

4) Fold the loose end of the liner fabric back across thefill placed in step 3.

5) Place and compact sand tailings to fill the trench andgrade the surface to restore it to original crestelevation.

The anchor trench around the pump station, shown on Drawing EP4,shall be excavated by hand or by equipment of the Contractor'schoice that will not disturb the concrete rim of the pump stationor the buried electrical conduit.

All fill compaction in the anchor trench shall be by hand-controlled, walk-behind tamping-plate or vibrating drum compactors.The trench backfill shall be compacted to not less than 108 pcf drydensity.

8


PART 3 - QUALITY CONTROL

The Contractor shall take the measures necessary to achieve allrequirements of Part 2 of this specification. These measures shallinclude, as a minimum, the following:

3.01 Supervision

During all times that the Contractor's equipment or personnel areperforming Included Work on the job site, a Contractor supervisorshall be present to direct the work. The supervisor shall haveexperience, satisfactory to HMC, in the type of work beingexecuted. The supervisor shall have on-hand at all times a copyof the current revision of this specification and the drawingsrelevant to the work. The supervisor shall have the authority tomake decisions for the Contractor in all matters related to parts2 and 3 of this specification.

3.02 Field Testing of Liner

The Contractor shall perform all field measurements and tests todetermine that the liner conforms to the requirements of thisspecification and the specifications and procedures of themanufacturer(s). The following minimum measurements and testsshall be performed:

Membrane Thickness

Measure and record the thickness of the membrane in at least onelocation within each 10,000 square foot section of liner and withineach 100 square foot section of the pump station (not includingpump foundation surface area). The Contractor shall establish agrid for this purpose, illustrated on a scale drawing of the linerarea. The measurement points shall have alphanumeric designationsthat identify the liner section and the point location within thesection. At its discretion HMC may direct the Contractor to repeatmeasurements or take additional measurements.

Liner Properties

Test not fewer than 10 test patches (one for every 100,000 squarefeet of liner), one at each 10% increment of liner membraneinstallation, for each of the properties listed in section 2.01 ofthis specification. Each test patch shall be a piece of linerfabric, at least four square feet in area, covered by at least 90mils of sprayed-on membrane. Tests may be conducted by theContractor on the job site or by an independent testing laboratory.

Any test patch on which one or more properties fail to meet thespecified minimums may be retested. If the patch again fails, apiece of liner section represented by that patch shall be removedfrom the liner and tested. If that piece also fails, the entire

9


100,000 square foot section of liner shall be replaced either byremoving it and installing another section, by covering thatsection with a second layer of liner, or by applying additionalthickness of membrane. The choice of corrective measure willdepend on which properties are deficient, will be recommended bythe Contractor, and will be implemented if accepted by HMC. Anysection of liner that is replaced or corrected will be retested inthe same manner as the original liner. Corrective measures andtesting will-be at the Contractor's expense.

10


PART 4 - DOCUMENTATION

4.01 - Documentation by Contractor

The Contractor shall record and report, in a format acceptable toHMC, the following information:

Daily journal containing a list of equipment and materialsused, amount of liner fabric and membrane installed, andanchor completed. List tests performed and pass/fail results.Submit by the start of the next working day.

Daily Work Summary listing all pay items and quantities.Submit by the start of the next working day.

Results of all tests on liner materials and installation.Submit within 24 hours of test completion.

Written notifications to HMC cf unexpected conditions,conditions that prevent confo-rmance with specifications,disputes over acceptance of Contractor's work. Verballynotify HMC immediately upon discovery or identification,submit in writing within 24 hours.

4.02 - Documentation by HMC

HMC will create and maintain the following documentation thatrelates to the Included Work:

Field inspection notes of Contractor's performance, workaccomplished, and variances from the specifications observedby HMC.

Records of all field and laboratory tests performed by HMC andits testing service.

Photographic and video tape records of the Included Work.

Chronological record of notifications to the Contractor ofvariances from specifications, unacceptable work performance,discrepancies in payment quantities claimed by the Contractor,and all related resolutions thereto.

As-built drawings of completed work.

11


PART 5 - ACCEPTANCE AND WARRANTY

HMC shall have sole discretion to accept in part or in full, or toreject in part or in full, the Contractor's work. Acceptance orrejection will be based on HMC's visual inspections (includingthose of its Engineer and testing service), quality control datarequired under Part 3, and documentation required under Part 4.

Upon identification of unacceptable work, HMC will notify theContractor of the deficiency. The notification will include thelocation, extent, and description of the unacceptable work. Beforeproceeding with additional work at that location the Contractorshall correct the deficiency by bringing the work into compliancewith specifications and drawings to the satisfaction of HMC. Allwork and materials required for such corrective actions shall beat the expense of the Contractor.

HMC's acceptance of the Contractor's work shall not release theContractor from its responsibility for the durablility andperformance of the liner. The Contractor shall provide a writtenwarranty covering all materials and workmanship of the liner for15 years from the date of acceptance. The warranty shall obligatethe Contractor to repair or replace the liner at its own expenseif defects are discovered in the liner during the warranty period.For the purposes of this warranty, "defects" shall includematerials and workmanship that do not meet these specificationrequirements (Part 2) as well as any subsequent deterioration(e.g.; cracking, disintegration, corrosion) of the liner.

12


PART 6 - SCHEDULE

Complete the Included Work within 90 calendar days according to thefollowing schedule:

Notice to Proceed Day 0Commence mobilization Day 15Complete mobilization and task 2.01 Day 30Complete installation tasks (2.02) Day 90

Weather conditions that prevent work on a specific task for anentire work day shall be accommodated by a day-for-day extensionin the schedule of that and other directly affected tasks.

13

V1- "inyard & Associates, Inc.

A

4415-D Hawkins, NEAlbuquerque, New Mexico 87109

(505) 345-1937

Geotechnical Engineering * Materials Testing * Environmental Engineering

May 30, 1990

AK GeoConsult, Inc.13212 Manitoba Drive, NEAlbuquerque, New Mexico 87111

Attention: Mr. Alan Kuhn

Subject: Laboratory Testing, Homestake MiningVinyard & Associates' Job No: 90-1-44

Gentlemen:

Attached are copies of the laboratory test results for the subject

.)roject.

Should you have any questions regarding this data, please do not

hesitate to call.

Sincerely,Vinyard & Associates, Inc.

M ' y

Martin D. Vinyard, P. E.

Attachment: Data Sheet (8)

.c: Addressee (2)

V

ACOMPACTION TEST RESULTS

140

130

120

110

L6~

U

100

900 5 10 15

MOISTURE CONTENT (%)

20 25 30

AMPLE LOCATION: Composite -

SOIL DESCRIPTION: SAND, sligh

UNIFIED SOIL CLASSIFICATION: s

AASHTO SOIL CLASSIFICATION:

TEST METHOD: ASTM D-1557

ATTERBERG LIMITS: LL NV

ON-IF-A + flN-21F-I

tly silty

'- SM

0 PI NP %

_SIEVE ANALYSIS - % PASSING1 1/2" 3/4" 3/8" No. 4 No. 8 No. 16 No. 30 No: 50 No. 100 No. 200

100 99.9 99.9 95.2 36.6 11.1

Project No: 90-1-44Figure

v&A

COMPACTION TEST RESULTS

140

130

120

110

z

z

100

900 5 10 15


20 25 30

'A.MPLE LOCATION: Composite -

SOIL DESCRIPTION: CLAY, sandy

UNIFIED SOIL CLASSIFICATION: CL

AASHTO SOIL CLASSIFICATION: -


ATTERBERG LIMITS: LL 32

ON-3E-B +* IN-3E-B

% Pi 14 %

SIEVE ANALYSIS - % PASSING1 1/2" 3/4" 3/8" No. 4 No. 8 No. 16 No. 30 No. 50 No. 100 No. 200

100 99.9 99.8 99.4 92.7 81.2


V&A


140

130

120

110

z

100

900 5 10 15


,AMPLE LOCATION: Composite - ON-5E-A + ON-4E-A

SOIL DESCRIPTION: SAND, very silty

UNIFIED SOIL CLASSIFICATION: SM



ATTERBERG LIMITS: LL NV % P1 NP

20 25 30

%.... .v

SIEVE ANALYSIS - % PASSING1 1/2 3/4" 3/8" No. 4 No. 8 No. 16 No. 30 NQ. 50 No. 100 No. 200

100 99 97 63 39.1

Project No: 90-1-44

Figure

V


140

130

z

U

z6=aJ

120

110

100

900 5 10 15 20


30

AMPLE LOCATION: ON-5E-B

SOIL DESCRIPTION: SAND, very

UNIFIED SOIL CLASSIFICATION:



ATTERBERG LIMITS: LL 28

clayey

Sc

% PI

SIEVE ANALYSIS - % PASSING

1 1/2" 3/4" 3/8" No. 4 No. 8 No. 16 No. 30 No,. 50 No. 100 No. 200

100 98 68 45.6

Project No: 90-1-44

Figure

V


140

130

U

z

120

110

100

900 5 10 15 20 25 30

MOISTURE CONTENT (%)Composite - IN-3E-A + IN-2E-A

SAND, very silty

\MPLE LOCATION:

SOIL DESCRIPTION:

UNIFIED SOIL CLASSIFICATION:



ATTERBERG LIMITS: LL Nv % PI NP %

SIEVE ANALYSIS - % PASSING

1 1/2" 3/4" 3/8" No. 4 No. 8 No. 16 No. 30 No. 50. No. 100 No. 200

100 99.9 99.9 96.6 55.9 29.2


V&A


140

130

U)120

110

100

900

I

5 10 15


20 25 30

-.AMPLE LOCATION: Composite -

SOIL DESCRIPTION: SAND, very

UNIFIED SOIL CLASSIFICATION: s



ATTERBERG LIMITS: LL NV

2N-2W-A + 2N-llq-A

silty

m

% PI NP

SIEVE ANALYSIS -% PASSING

1 1/2" 3/4" 3/8" No. 4 No. 8 No. 16 No, 30 No. 50 No. 100 No. 200

100 99.0 98.9 98.8 98.7 98.5 95.5 56.0 28.1

Project No: 90-1-44

Figure

V&A


140

130

LU

120

!

110

100

90 0 5 10 15 20 25 30

MOISTURE CONTENT (%).jAMPLE LOCATION: 2N-5W-A

SOIL DESCRIPTION: SAND, very.

UNIFIED SOIL CLASSIFICATION: SM



ATTERBERG LIMITS: LL Nv

silty

% PI NP %

Project No: 90-1-44

Figure

V SUMMAR r OF LABOi.A-iTORY E tST DATA

SIEVE ANALYSIS% PASSING BY WEIGHT

3/4- 3/8- No.4

NO.8

NO.16

No.30

No.50

No.100

NO.200

UnifiedClassi-Fication

DESCRIPTION

ON-lE

ON-3E-A

ON-3 E-B

ON-5E-A

ON-5E-B

IN-IE

IN-3E

IN-5E

2N-lW-A

2N-lW-B

2N-3W

2N-5W

3N-IE

3N-3 E-A

3N-3E-B

3N-5E-A

9

13

NP

31

100

100

100

100

100

100

100

99

100

99

100

100

100

99

100

100

94

95

100

97

98

97

97

96

97

100

96

97

93

97

100

28

55

96

64

68

68

60

62

60

87

57

61

43

66

98

6.2

30.7

91.1

40.0

45.6

45.1

29.0

37.1

34.6

65.6

34.3

38.8

24.5

44.3

97.4

SP-SM

CL

SC

CL

SM

CL-CH

SAND,

CLAY, slightly sandy

SAND, very clayey

CLAY, very sandy

SAND, very silty

CLAY, slightly sandy

slightly silty

97 154 29.61 -

- I - J. - .1............. - J - - - J. ..........~L.............. .L - I -

Project No. 90-1-44Table 1

"6570.8

--- -- 6577.5 •---- 659 ,aI V-... ~~ f_- ..- , 575.2 -, ...... ,--,.5:. 5 A

-//, ~ ~~ ~~~ ~ ... .......... .... ........ ....... __/,, .. - ::.: .•:!.-"" " .. . " ..... : " . ; •..;i,•,; ,o .• ; • ;z -',• -. ;. ,, -;" 7

-650. \ 0'! !

N -LEGER

7

Area of

.Area ofLi

6

RESULTS OF LABORATORY TESTS ON BORROW SOILS

HOMESTAKE MINING COMPANY, GRANTS. NMTAILINGS STABILIZATION AND RECLAMATION PLAN

TEST PIT SOIL SAMPLE TEST PROGRAM, SEPT 1987

FAGE I

TEST PIT/ SOILSAMPLE NO CLAS

TP 10/1JI

TP 10/B1 CL

TP 12/31

TP 12/BI CH

TP 12/32

TP 12/B2 CL

TP 13/JI

TP 13/B1 CL

TP 13/J2

TP 13/B2 CL

TP 14/31

TP 1-4/81 CH

TP 15/I1

TP 15/B1 CL-CH

TP 17/1JI

TP 17/B1 CH

TP 18/31

TP 18/B1 CL-CH

TP 19/31

TP 19/BI CH-CL

TP 20/1J

TP 20/B1 CL

TP 21/J1

TP 21/1BI CH

TP 22/1JI

TP 22/B1 CL-CH

TP 2/31I

TP 23/B! CH-CL

TP 24/J1

TP 24/BI CH

TP 25/J1

WATERS CONTENT

18.04

21.91

22.97

15.61

10.54

11.34

12.84

14.24

12.15

1.2.73

7.91

16.24

14.69

9.45

.16.35

8.73

ATTERBERSLIMITS

LL/PI

46.5/25.4

73.6/48.4

35.1/19.9

45.9/24.6

30.5/ 15. 4

52.7/29. 0

48.7/27. 6

56.5/32 .3

478 / 22

53.,4/31.8

28.9/13.5

58.5/34.1

49.8/29. 3

51.1/27.4

67.2/41.9

USED INPROCTORTEST NO.

COMP I

COMP I

COMF I

COMP I

COMP 2

COMF' 2

COMPF

COMP 4

COMP 4

COMP 5

COMP 5

COMP 5

COMP 6

COMP 6

TP 25/Bl CL 25.5/11.4 COMP '7

RESULTS OF LABORATORY TESTS OF BORROW SOILS

TEST PIT/ SOIL WATER ATTERBERG USED INSAMPLE NO CLASS CONTENT LIMITS PROCTOR

% LL/PI TEST NO.

TF .26/31 13.47

TP 26/BI CL 45.4/25.1 COMP 7

TP 27/J3 9.75

TP 27/BI CL 22.7/8.7 COMP 7

TP 28/31 15.42-- -4 -- -- --- -- -

TP 28/B! CL-CH 47.2/28.0 COMP 3

TF 39/31 12.93

TP 30/B1 CH 54.5/31.4 COMP 4

TP 31/31 17.06

TF' 31/B1 CL 42.2/24.) COMF' 2

TP 33/B1 CH-CL 53.6/31.7

GRAIN SIZE -#4 -#10 -#40 -480 -4200

TP 33/B2 100 100 95 28 6.0- - -- - - - --- - ---- -----

TP 34/81 100 1902 93 81.

PAGE 2

COMPOSITESAMPLES

COMP 1

COMP 2

COMP 3

COMP .4

COMP 5

COMP 6

COMP 7

GRAIN SIZE-----SIEVE HYDROMETER

-t10/-*49/-#200 -. 005/-.001

100/94.4/84.0 60.2/44.4

100/94.9/85.6180/97.3/83.3

100/96.2/9I2.1

100/96.9/84.2

66.3/50.0

71.1/56.6

77.6/55.8

63.0/49.1

STD. PROCTORMAX. DRY

DENSITY.PCF

102 .

192.0

94.1

93.7

99.3

99.5

196.3

OPTIMUM PERMEABILITY DISPERSIVITYMOISTURE PINHOLE CRUMB

(E-08 cm/is)

20.3 1.69 DI 2

19.3

2. 0 3.84 ND3 I

13.5 1.59 NDI I

20. 0 .502 ND2 I

20.0

18.5 1.51 NDI I-- - - - - - - - - -

_"__==__ _- _________.. .... ___________________PUMP STATION -- 6576.9 1/)- - - - -_ _ •(See -Drwg. EP4) =, 65787 6•5-/ 7 // ,7-I-.

b *-.. "6580

s6573-4--6570

6570.4

L i-N-

SCALE 1"= 200'

1.3 x

LEGEND

6575.3

I EXCAVATIONPOND CREST ELEV. 6599.1

D FILL (including minor gradingof existing surfaces)

ROADWAY/

APPROXIMATE LIMIT...OF EARTHWORK /

EVAPORATION SPRAYSYSTEM

6572.4 x NOTES

59 C

ý 0 DISPOSAL AREA a--7-

"\6S %7. 1 TEST FILL AREA1.57679L575 ~6579.i659 67.

K66501 6576 III71-0 5 7 6 6571. 1

.. '.. :::.....":: : . '. i "" :.' . ' '' . • :!: . '...' : " ".. '; ' :-' '•":1'''; • . ' ?- ' -,.'• l " ' i , • \ ' • ", - '• •. Z \ - ; -\J -, •' " .. .0 0

1) LOCATION, SIZE AND CONFIGURATION OF EVAPORATION SPRAYARRAYS AND COMPONENTS ARE VARIABLE AND WILL BE CHANGEDBY HMC AS IT DEEMS APPROPRIATE. ARRAYS AS SHOWN AREREPRESENTATIONAL ONLY.

2) POND OUTSLOPE IS 5H:IV EXCEPT SOUTH DIKE (3H:IV) ANDNORTH OUTSLOPE AT PUMP STATION (3A4H:IV.

3) POND INSIDE SLOPE IS 4H:IV EXCEPT NORTH SIDE (10H:1V).

4) SEE DRAWINGS EP2 AND EP3 FOR SECTIONS A-A' THROUGH E-E'.

5) WATER PIPELINE, TO BE INSTALLED BY HOMESTAKE, WILL BEENCLOSED IN LARGER FROM TOE OF OUTSLOPE TO POND SLOPE.

6570.9

6568.9K

x6573. 3

6568.8,

x 6571.4 6573.0X

I:,

WEST

6600 -

EASTLINER ANCHOR

•LINER P N AE 'EE 60................... MAXIMUMPO WTR'VL .- 6

1: Ms - - - - - - - - -6590

IN.PLACE TAILINGS -6580

.. .. .. . . . . ... 0

... ... ... .. ... ... .. ... ... .. . .. . . 6 5 7 0..... . . . .. .. ........ . . . o........................... .. .... ...--. -.-.--.-..-. --.,-.. ..'-...............•,.. ..:••.i•:,....-.. .-.. i,•.., • • . s7:: :•:•: ii: :i:•: :: :! ii :i i:i i:i •: :: :i:• i:i: i ii: :•:• : :::: :: ::::: ::::::: .......................i ii i i ii i ii i • ii i i !! !:~ i: :i:!: :: ::::: :::: :::: :: ::::: ::::: :: :: ::i: :: :i:• i i

SCALE 1"=20'

SECTION A-A'

SOUTH

•6600-

6590-

NORTH

-6600

-6590

EXISTING PILE SURFACE .' . .

6570. .... .... . . . . . . . . . . . . . . . . . . . ... .. .... .. . ....... .

. ................ . .. . . .. . . .. . . .. . .. . . .. . . .. .._ _ _ _ ................................. . . . . ..• . , = ...-.• • . • •.. . -.., ...• •. - .... ::..:.. . ..... . . .........: :.:.. c................ .. . .... ...... . ....... - .... . ...... . ..... ... ... .... ... ....... . . :. ... .... ....:... . .. ...... . . . . . . . . . . . . . . ` ` . . . ` . . . . .` ̀ . . . .... . . . . . . . . . . . . . .. . . . .. . . . .. . . .. .. . . . . . . . . . . . . . .. .. .. . . . . . . .. . . .. . . . . . `. .. . . .` ... ̀ . .... . ...... .`. ̀ ̀ ` ... ... ..` ̀ .` . . . . . . . ..... ... ... .`. .. .. . . . ..... . . . .... . .. . .. ... . .. .... . . . .. ... ... ..` ... `... .. . .`` ̀.. ... ..̀ ... . . .... . .. ... . .. ... .. . ... . ..̀. .. ... ... ... `. ..` ..`.. .. ̀ .. ... ..̀ .. .``.....`.

...................................... `.........`.....................................................................................`. ..................... ...............̀................................`...........,................................................................................................

NOTES

1) Fill placed over original outslope oftailing pile containment dike will benatural soil. All other fill will betailings excavated from pond area.

2) See Drawing EP5 for liner and liner

anchor details.

3) Maximum Pond Water Level is elev.6597.1 tminimum freeboard 2.0').

SECTION B-B'

WEST EAST DRAWING EP26600- MAXIMUM POND WATER LEVEL - 6600

650 -- -- ....- -------------

EXCAVATION

= .. .:• !.!i•::••i::•::';•,•,-':::•:: :••!?i::::::: :•;!:•!!:•1rfi ;i• • : :L• : :!t:.,•:•:! • IA-IU-:;:!::: :b:b•;

65 0 .. . .. ....... ..:;:o -- ..:: .:: :::!........:.:: .:- ..•': .•.-:;•::. . ...-.- •. :. .: .;'.....;!... ....."..': ..- . . . ...... .I.• L A ; : ... .. ..........

. . . .. ..... ... ,.. .. ,... .. ,..:. .: . . .. .:. :.. ... . . ,: ....,, .= ., . : . .; .• . :.......... ... . . . .. . ...........:............ ." ' .. .. ....e e .'. . .'. . . . .- - . . '.. . . . . . . . . . .• .'.• .. .........

.......... ............... ...................................::::: ::: :: :: :::::::::::::• •:::::::::::::::::: ::

'-""::: ':"i;::.- . ......... . ...

_ .: .. •.......•.:.:..

EXISTING PILE SURFACE - 590

-7-6580

SECTIONS OF POND DIKE

EVAPORATION POND, GRANTS MILL

A KGeoConsult I

FOR

HOMESTAKE MINING COMPANY

DAE 4/30/90 K o.. : 0

SECTION C-C'

1.

_• I'll ITH LINER ANCHOR •N-T

EXISTING PILE SURFACE LINER.1 ___ /_ FILL 60

6600- MAXIMUM POND WATER LEVEL - - - - - -- 6600- IV

sh- V- 6590

IN-PLACE TALIGSINTAIMN .. E...

.. . . ..5...80. . .. . .. e - - 6 8. . . . . . . . . . . ... . . . . . . . . . . . . .. .. ............ . .. ....N

6580 -~~~ 6570... ....

• ....... .. :•...:...... ..: . .........:...............-........................ ....................................................................'.........::...............................'..''.......,,,.--,.,,.-........"-.'-..'...,,...-.....-.,.-.........'',.-..,...,,,,.......'...,.-..'.,,....,....,....

" .'•::!:...:'!" ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ . ........... .................................................. .... .............'. ..". ..". . ...... . . .' ... ...... .........i•..•. . . . : :• • : : :• • •: : :• • •: : :- -: : :•-:- - :• " • : :' ': : : ': ;: " ': : :' ' ;' ' :' ' ': : :' ":' '• ' ' " ' " ' 'i ... ... ....2:": : : ' ':" : : : : " ';:':":{i :: :

SECTION D-D'

SOUTH

6600-

EXISTING PILE SURFACE

MAXIMUM POND WATER LEVEL"LJ. 0l................ ..................

6590- EXCAVATION H:

IffPLACE TAILINGS6580-

...- .. ... .... ...... ... ........ ........ .............................;; !i iii.i{ { •;•:~ii~ii:i~i:{ ii•~ ~i:••;i,:•i~ :;!:i•:~ '!!•! : :;!:; !i{ii /: iii~ :i•: •• I:•,• ::•ii;:• !i~~:• ..... .... ... ...

6570............ ......... Ie W... .. ....... .~Sp~ ...........t SfrZ.MflCA . . .....-

6570- ... : :R:: :: : ::

SECTION E-E'

SCALE 1"=20'

DRAWING EP3

NOTES

1) Fill placed over original outslope oftailing pile containment dike will benatural soil. All other fill will betailings excavated from pond area.

2) See Drawing EP5 for liner and liner

anchor details.

3) Maximum Pond Water Level is elev.6597.1 (minimum freeboard 2.0').

SECTIONS OF NORTH DIKE OF

:EVAPORATION POND

GRANTS MILL

\O•.exConsult, Inc. .~. ..

FOR


cc 4/30/90 n•c ,, 0

A ..

-N"I A : il".:i.:•:: ::. ::'! i''. i.:.':: '-::":-: .'.:. !':!.•i: -::!i::!!!!i: :: . • .!.. .. i i li-'i- :'! :!- i:.: i:•i:'.:i' :.::i• ..::-'i.:LIN:! :!?f

• :: > .: "::: :.: :-:?.::...'. - .-. •:... i..-: ? :.:i.::% .:F '!:" ::':::. ::..': .i:':-.: .-!:i.:.: .'::'..?:.::..::': : f ?i:: .':.'F.':• .:.:':.! '-':i: : .: ' :'

NOTES

1) Two each 2 1/2" and one each 1 electricalconduit, 8" c/c, installed from outslopethrough fill to north side of each pumpfoundation.

2) Liner seal around pump foundations andconduits will be thickened section ofsprayed-on Deery Membrane #6 (Drwg. EPs).

3) Concrete rim is min. 2000 psi, sernicylindricalprecast segments or cast-in-place, at least 0.5 feethigh by not more than 2.0 feet wide.

PLAN OF PUMP STATION1"=40'

LINER

*. ......... . ni.~..4.. . . ........

.. . ......... . . ...\....... . . . ........ . . . . .

*~5~( c~ff~'~gf5j ~ '-~ \\ ELECTRICAL cONDUITCP.

F7 A FttrjV~4 ---)1A < 4'

Pump- , -4.4.AA

t'-" 4 6A ' V<7-LINER

L 162

< 3% TO 5% SLOPE 2.0"

LINER THICKENEO MEMBRANE SEAL I

/ •/I 1.0 MIMIN.

.T. G-G'

SECTION G-G'

LINER.

PUMP STATION DETAILS

SCALE 1"=5'

DRAWING EP4

PUMP STATION


-- M1 5' I•.- / M ' THICKENED MEMBRANE SEAL LINER CONCRETE RIM- 0.5 LINER ANCHOR

SECTION F-F'

.¢, ..................................

FOR


1,, . 4/30/90 RE NG.." 0

LINER DETAILSCALE - ACTUAL THICKNESS X 2

LINER MEMBRANE (see Note 1)

LINER FABRIC (see Note 2)

SAND TAILINGS, MIN. 1.0'% COMPACTEDTO AT LEAST 108 PCF DRY DENSITY

Variable, I- to 4' Shape and width of anchor trenchdepending on the depends on equipment used toequipment used to excavate IL Configuration

lexcavate trench. shown is made by grader.

LINER MEMBRANE

1.0' MIN.

NOTES

1) Liner Membrane is Deery Membrane #6, sprayed in layers to formtotal thickness not less than 90 mils (0.090').

2) Liner Fabric Is 60 mils Trevira spun-bond polyester, minimumgrade 1112.

3) Cable anchor shown is deadman type; may vary or change to includeother types.

4) Used conveyor belt or heavy-duty matting will be placed undercable to protect pond liner and dike crest against abrasion by cable.

LINER FABRIC

LINER FABRIC ANCHOR TRENCH

LINER ANCHOR DETAIL

1= 2'

DRAWING EP5EVAPORATION SPRAY SYSTEM CABLE AND PROTECTIVE MAT (see Note 4)

,/1

/LINER ANCHOR

CABLE ANCHOR

DETAILS OF LINER


U\\GeoConsult. inc ..... .

FOR


D••E. 4/30/90 K ,u. 0

ANCHORAGE FOR EVAPORATION SPRAY SYSTEM

1"=10'

r

04I

0) SURVEY POINT COORDINATES

Lu NW WI PSI PS 4 N 90' E NE 'U- - - - - - - - -- - - - - - - - - - - -POINT N E Elevation

/ 111 - O, • 6 NW 1542257.5 491799.7

RP2 2R 1542257.5 492696.7SE 1541209.1 492663.2SW 1541411.1 491144.9CL

RP1 1542198.7 491828.47. , .T R6 =4a.4' RP2 1542201.6 492639.0

NP 15400 RP 14267955.N 1542000 _ _ _ _ _ _RP4 1541460.4 491265.5* RP5 1542037.7 491784.2

RP6 1542040.6 492569.7RP7 1541331.3 492556.3

I RP8 1541481.0 491316.2

IL 1542230.3 491788.0 6599.1DL R 1542250.0 491828.4 6599.1

2L 1542250.0 492639.0 6599.12R 1542200.1 492687.4 6599.13L 1541284.7 492656.5 6599.13R 1541225.9 492587.1 6599.14L 1541403.7 491257.0 6599.141 1541495.6 491220.4 6599.1

5L 1542069.3 491743.8 6583.05R 1542089.0 491784.2 6583.0

6L 1542089.0 492569.7 6583.06R 1542039.1 492618.1 6583.07L 1541330.2 492591.3 6583.07R 1541296.6 492551.7 6583.08L 1541461.1 491313.6 6583.0

R B 8R 1541493.3 491300.4 6583.0

? aPSC 1542258.0 492215.0R4=57.2' PSi 1542265.0 492056.0 6599.1

SW ( PS2 1542286.0 492196.0 6599.1PS3 1542286.0 492234.0 6599.1

RP7 PS4 1542265.0 492274.0 6599.1

7R.RP3 3L EXISTING CONTROL POINTS

R1 1545033.75 493107.50 6586.011542710.57 493067.24 6581.571542724.70 488900.03 6577.11

SE 1545137.31 488909.36 6582.62

N 1541000 DRAWING EP6

LEGEND NOTES 1 SURVEY POINTS

RP Radius point (center) of circular curve 1) Elevations relative to M.S.L., National Geodetic Datum FOR LINE AND GRADE CONTROL


R Radius of circular curve 2) All coordinates refer to New Mexico State Plane Grid, West Zone.

Centerline of dike crest 3) Listed coordinates are rounded to nearest 0.1 feet. An'GeoConsu..~'\Gooil.Inc. ... ... .

....... Radius at end of circular curve FOR

PSC Center point of middle foundation HOMESTAKE MINING COMPANYof pump station SCALE 1"=200' O' /0S O______

- - - - - - . - -

I I I I I II I I I I I

II 1 I. I ! ONE MAT OF #4 REBAR, 12" O/C EACH WAY

PUMP CENTERLINE

i-- -lH' L 6'

# I 14I I I I i I I I " " . .

/[

MIN. 4000 psi CONCRETE SECTION I-I'

/ ANCHOR BOLTS, 5/8" DIA. 14" LONG WITH 3" HOOK THREAD 3" ABOVE BASE,

"'7 8 EA REQUIRED EACH PUMP BASEDESIGN GRADE, 4 19" 20" 18" 20 19"'-6-

ELEV. 6599.1 PUMP BASE IS D-1000, 8'x 6'x 13"p 0'• 9 18"an8 ___________________

SECTION H-H'

PUMP FOUNDATION DETAILSEVAPORATION POND

SCALE: 21 APPROVED BY: DRAWN BY

DATE : 4/30/90 REVISED


GRANTS MILLDRAWING NUMBER

Jo EP7

am.X 11 PRINTED ON NO. 10OOH CLEARPRINT.

Documents

OFFICIAL DOCKET COPY · submit an amendment request to NRC Source Material License SUA-1471. In fulfill ment of i1cense condition -315D Homestae.. sonits, .cr NRC ... layout of the