DRAFT FINAL MONITORING PLAN FOR SITE-WIDE ...Draft Final Site-Wide Groundwater Monitoring Plan Operable Unit 12 - California Gulch NPL Site Pagel 1.0 INTRODUCTION This Groundwater

rSDMS Document ID

1020443

DRAFT FINAL

MONITORING PLAN FOR SITE-WIDE GROUNDWATEROPERABLE UNIT 12

CALIFORNIA GULCH NPL SITE

PREPARED FOR REGION 8 USEPA

HDRNOVEMBER, 2002

TABLE OF CONTENTS

1.0 INTRODUCTION 11.1 Background 11.2 Current Monitoring Programs 11.3 Responsibilities 2

2.0 OBJECTIVES 23.0 MONITORING PROGRAM COMPONENTS 3

3.1 Constituents of Concern : 33.2 Sample Measurement, Location, Frequency and Rational 4

4.0 FIELD SAMPLING PLAN 85.0 DATA MANAGEMENT, TRANSMITTAL AND REPORTING 86.0 REFERENCES 9

LIST OF TABLES

Table 1 - Groundwater Maintenance SummaryTable 2 - Laboratory Analyte ListTable 3 - Groundwater Monitoring Plan SummaryTable 4 - Well Information Summary

LIST OF FIGURES

Figure 1 - Current and Historic Groundwater Sampling LocationsFigure 2 - Groundwater Monitoring Locations

Draft Final Site-Wide Groundwater Monitoring PlanOperable Unit 12 - California Gulch NPL SitePagel

1.0 INTRODUCTION

This Groundwater Monitoring Plan (Plan) describes a program to collect ground-waterlevel and quality data for Site-Wide Groundwater in Operable Unit 12 (OU12) of theCalifornia Gulch National Priority List Site (NPL Site).

1.1 Background

The United States Environmental Protection Agency (EPA) proposed adding theCalifornia Gulch Site to the NPL on December 30,1982. The site was formally listed onSeptember 8, 1983 (CDM, 1997). In 1994 the United States, the State of Colorado, andthe Potentially Responsible Parties (PRPs) entered into a Consent Decree (CD). The CDdivided the NPL Site into 12 OUs for the cleanup of geographically tesed areas withinthe site. The CD required the PRPs to implement Source Remediation within specificwork areas assigned to individual PRPs and EPA. These work areas included OU1through OU11.

Unlike the other OUs, OU12 encompasses the entire NPL Site and is intended to addressSite-wide surface and groundwater should Source Remediation not achieve the RemedialAction Objectives (RAOs - see OU12 Feasibility Study) for Site-wide surface andgroundwater. The CD delineates OU12 groundwater as groundwater occurring abovebedrock or within 250-feet of the surface, whichever is less, across the NPL Site. The CDrequires that Source Remediation be implemented before a ROD is issued for OU12.

As the Source Response Actions approach completion, it becomes necessary to assess thesurface and groundwater quality against the RAOs for Site-wide surface and groundwaterto determine whether or not the prior Response Actions have achieved the RAOs.Historical and current monitoring of groundwater quality and elevation has beenperformed by multiple parties across the NPL Site. However, these efforts were focusedlargely on evaluating the performance of Source Response Actions in specific OUs (seeSection 1.2). The monitoring described in this Plan does not substitute for performancemonitoring of specific remedies implemented under existing RODs. Rather, this Plan isintended to assess groundwater quality trends at a select number of locations within theNPL Site believed to be indicators of the quality of Site-wide groundwater.

1.2 Current Monitoring Programs

Groundwater has been, and continues to be, monitored by the Colorado Department ofPublic Health and Environment (CDPHE), Resurrection Mining Company(Resurrection), ASARCO, Inc., and USEPA. In general, CDPHE monitors groundwaterthroughout the NPL Site; Resurrection/ASARCO conduct groundwater monitoring inspecific work areas assigned to each of these PRPs; and EPA conducts groundwatermonitoring in fluvial tailings deposits along the Arkansas River.

Draft Final Site-Wide Groundwater Monitoring PlanOperable Unit 12 - California Gulch NPL SitePage 2

Table 1 and Figure 1 summarize the scope of current and historic groundwatermonitoring in the NPL Site.

1.3 Responsibilities

To be determined

2.0 OBJECTIVES

The objective of this Plan is to monitor Site-Wide groundwater quality to assess thepotential for groundwater to contribute to metal loading of surface waters, specificallyCalifornia Gulch and the Arkansas River. The focus on impacts to surface water qualityis driven by concerns ever aquatic ecology. The potential for human exposure tocontaminated groundwater via a water well or through exposure to surface water derivedfrom groundwater is also of concern. However, these exposure pathways are notaddressed in this Plan for the following reasons:

• It is technically impracticable to delineate and monitor all exceedences of waterquality standards for groundwater across the 16.5 square-mile NPL Site in threedimensions and with confidence.

• The Baseline Human Health Risk Assessment - Part B (EPA, 1995) concludedthat human exposure to surface water (derived from discharging groundwater orotherwise) is of sufficiently low concern that the exposure pathway was notevaluated.

• It is anticipated that potential human exposure to groundwater via a water wellwill be mitigated through a health advisory or other institutional control designedto discourage the use of water wells for water supply and/or require testing priorto well completion. The health advisory or other 1C would apply to the entire NPLSite.

Data collected under this Plan will be used to determine if metal loading to surface watersby discharging groundwater is sufficiently high to warrant remedial action under anOU12 ROD. The data may also be used to identify specific geographic areas contributingthe highest metal loading rates to surface water.

A groundwater remedy under OU12 would be considered under the followingcircumstances:

1. Surface water RAOs are not met by prior and upcoming Source ResponseActions.


2. A Feasibility Study determines that a groundwater remedy is more appropriatethan additional Source Remediation or surface water treatment. A groundwaterremedy may also be considered in addition to Source Remediation or surfacewater treatment.

Three potential migration routes for groundwater discharge to surface water are ofinterest. Monitoring the current conditions and future water quality trends along thesemigration routes form the basis of this Plan. Potential migration routes include:

• Rising bedrock water levels potentially increasing discharge of bedrockgroundwater to overlying alluvium resulting in discharge of contaminatedgroundwater to surface water via seeps, springs, flowing mineshafts, and directdischarge of groundwater to stream channels.

• Unremediated mine waste deposits adjoining surface water bodies potentiallyloading significant metals to surface water via saturated alluvium.

« The shallow alluvium near the Apache Tailings (OU8).

Secondary objectives for this Plan include:

• Consolidating sampling efforts to eliminate duplication of data collection efforts.

• Providing a basis for establishing responsibilities under this Plan.

3.0 MONITORING PROGRAM COMPONENTS

s

3.1 Constituents of Concern

As presented in Attachment B of the Preliminary Draft RAOs for OU12 prepared byCDPHE (2001), seventeen potential contaminants of concern (COCs) were identified inrisk assessment documents prepared for the NPL site. These potential COCs include:aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, copper, gold,iron, lead, manganese, nickel, selenium, silver, thallium and zinc. Subsequent discussionsbetween EPA and CDPHE led to a final COC list as follows:

• Aluminum• Cadmium• Copper• Lead• Zinc


The full analyte list and EPA analytical methodology is presented on Table 2 and wasadopted from that performed routinely by CDPHE with the following exceptions:

• Dissolved metals are limited to the final COC list presented above.• Total cyanide, thiocyanate and nitrate/nitrite are excluded given no sampling is

proposed proximal to the Malta Gulch Tailings. These analytes were previouslydetected only near this tailings impoundment.

The analytes selected as COCs are based solely on aquatic toxicity. Monitoring waterquality for COCs specific to human receptors is not part of this Plan as discussed inSection 2.0.

3.2 Sample Measurement Location, Frequency and Rational

The objectives identified in Section 2.0 will be met through implementation of this Planin nine defined areas (Figure 2). Groundwater sampling and other measurements will beperformed at new wells proposed under this Plan, and existing wells and mineshaftsidentified on Figure 2 and Table 3. Table 4 provides well construction details, locationinformation, and the historical range of dissolved zinc concentration in groundwater foreach existing sample location.

A discussion of the rational for monitoring in each of the nine areas is provided below.

Area A - The intersection of the Penderv Fault and the Leadville Mine Drainage Tunnel(LMDT)

A rise in the potentiometric surface of the bedrock aquifer has been observed recently anddocumented in several reports (MFG, 1998 and EPA, 2002a). The effect has been mostnoticeable near the intersection between the Pendery Fault system and LMDT. Onepossible cause postulated by MFG and EPA involves the impoundment of groundwaterup-stream of restrictions in the LMDT caused by the suspected partial collapse of theLMDT. The impounded water causes a discharge to the Pendery Fault System, which inturn, causes a rise in the potentiometric surface in the bedrock aquifer around the LMDTand Pendery Fault system. The purpose of monitoring groundwater in this area is toobserve trends in potentiometric surface elevation as well as to detect the water qualitysignature of groundwater originating from the LMDT. Verification of LMDT mine poolwater migration along the Pendery Fault System will support remedy selection in OU6 aswell as monitor the performance of the selected remedy (see OU6 FFS).

Wells PZ-10 and BMW-3 constitute an alluvial/bedrock well pair proximal to the Pendryfault and the LMDT providing a suitable location for monitoring groundwater migratingfrom the LMDT mine pool (See Figure 2). However, the groundwater in both of thesewells displays elevated pH in the range of 11-13 suggesting the presence of groutcontamination. In addition, groundwater recharge rates less than one gallon per minute

Draft Final Site-Wide Groundwater Monitoring PlanOperable Unit 12 - California Gulch NPL SitePageS

(gpm) suggest that the well screens do not intersect appreciable fractures and may not behydraulically connected to the Pendry Fault System. Therefore, a new alluvial/bedrockwell pair is proposed for installation in Area A under the OU6 remedy and will beincorporated into this Plan. Water levels in PZ-10 and BMW-3 will continue to bemonitored until the replacement wells are installed.

Two additional wells advanced into the LMDT are contemplated for this area. This wouldallow comparison of potentiometric heads in the tunnel and water levels in the PenderyFault. The wells would be installed as part of an OU6 Response Action.

Groundwater sampling in Area A will be conducted twice per year in April and October(Table 3) corresponding to the low (April) and high (October) water stage in the minepool. Water levels will be measured at the time of sampling and on two other occasionsin June and August. Water levels in the Robert Emmett mineshaft wil) be measured four -times per year to monitor water levels in the LMDT mine pool until the new monitoringwells are installed in the LMDT.

Area B - The intersection of the Pendery Fault and California Gulch

The objective of monitoring in this area is similar to that for Area A. Groundwatermigration along the Pendery Fault System may have advanced as far as California Gulch.Some increase in calcium, magnesium, sulfate and total alkalinity with a concurrentdecrease in pH has been noted in this area (EPA, 2002a). This trend may be an indicatorfor an advancing plume of metal-impacted groundwater originating from the LMDT minepool.

The purpose of monitoring groundwater in this area is to observe trends in potentiometricsurface elevation as well as to detect the water quality signature of groundwateroriginating from the LMDT. Verification of LMDT mine pool water migration along thePendery Fault System will support remedy selection in OU6 as well as monitor theperformance of the selected remedy (see OU6 FFS).

Wells NW-5A and NW-5C will be monitored twice per year for changes in the verticalhydraulic gradient between the alluvium and the bedrock aquifers as well as for changesin water quality. This well pair lies along the Pendery Fault and is farther from theLMDT than Area A. Therefore, changes in water quality similar to those observed to datein Area A would suggest an advancing plume of metal-impacted groundwater originatingfrom the LMDT mine pool.

A second well pair may be installed along the Pendery Fault between Areas A and B. Thewell pair would be installed in alluvium and fractured bedrock proximal to the fault. Thelocation of this future well pair has not been determined and is not shown on Figure 2.

Groundwater sampling in Area B will be conducted twice per year in April and October(Table 3) corresponding to the low (April) and high (October) water stage in the mine


pool. Water levels will be measured at the time of sampling and on two other occasions,in June and August.

Area C - The Gaw and Valentine shafts

The Gaw and Valentine shafts have recently discharged groundwater at the surface forthe first time since the LMDT was constructed (MFG, 1998 and EPA, 2002a). Flow fromthese shafts may be related to the overall rise in bedrock groundwater.

The purpose of monitoring groundwater at these two features is to observe trends in thepotentiometric surface elevation inferred from the presence or absence of flow at thesurface. In addition, water quality monitoring at these locations (field parameters only) isintended to detect the low pH water quality signature of groundwater originating from theLMDT. Verification of LMDT min.e pool wafer discharging at these two features willsupport remedy selection in OU6 as well as monitor the performance of the selectedremedy (see OU6 FFS).

Although flow and water quality data from the Gaw and Valentine shafts is considered tobe of questionable value (EPA, 2002a), noting the presence or absence of flow and thecollection of field parameters will be performed in April, June, August and October.

Area D - The Lower California Gulch valley

Mine wastes have accumulated in the Lower California Gulch Valley adjacent to theGulch. These wastes have the potential to leach metals to shallow groundwater, which inturn may discharge to California Gulch and ultimately the Arkansas River. The purposeof monitoring water quality in this area is to determine trends. Although the valleyalluvium has not been previously identified as a significant source for metal loading tosurface water via groundwater, the migration pathway is potentially complete. Increasingmetal concentrations in alluvial groundwater may prompt further study to assess therelative contribution of this potential source to Site-wide metal loading of surface water.

Existing shallow wells close to California Gulch were selected to monitor the quality ofgroundwater potentially discharging to the surface water. Wells NW13A, NW11, NWSand NW15 have a top of well screen elevation within 27 feet of the ground surface andare between 25 and 150 feet from California Gulch. These wells will be monitoredannually for water level and changes in water quality. The monitoring event will occur inJune to correspond with the typical high alluvial groundwater stage.

Area E - Fluvial tailings along the Arkansas River below California Gulch

Fluvial tailing deposits downstream of the confluence of California Gulch and theArkansas River are currently being studied under OU11. Groundwater in existing shallowmonitoring wells is high in zinc and other metals (EPA 2002b).


These wastes have the potential to leach metals to shallow groundwater discharging tothe Arkansas River. The purpose of monitoring water quality in this area is to determinetrends. Increasing metal concentrations in alluvial groundwater may prompt further studyto assess the relative contribution of this potential source to Site-wide metal loading ofsurface water.

Wells UMW19, UMW01 and NW14 will be monitored annually for water level andchanges in water quality. The monitoring event will occur in June to correspond with thetypical high alluvial groundwater stage.

Area F - The Apache Tailings Area

Groundwater monitoring in this area is intended to identify water quality trends in theshallow alluvium near the Apache Tailings Response Action scheduled for completion in2002. It is desirable to take measurements in this area during high and low groundwaterstage. Therefore, well AP1TMW-23 will be monitored in June and October for waterlevel and changes in water quality.

Area G - Oregon Gulch

Groundwater monitoring in this area is to identify water quality trends in the alluvium.Alluvial wells along this drainage have contained groundwater with relatively high metalconcentrations. This groundwater discharges to alluvial groundwater in Lower CaliforniaGulch potentially discharging to the California Gulch Channel or the Arkansas River.Monitoring well OG1TMW-3 has contained groundwater with the highest historic metalsconcentrations in the NPL Site. Therefore, this well will be monitored in the spring orsummer for water level and changes in water quality.

Area H - Stray Horse Gulch

Groundwater monitoring will occur at the mouth of Stray Horse Gulch to assess waterquality trends in the alluvium. Although only relatively minor amounts of contaminationhave been observed in alluvial groundwater in this drainage, large quantities of minewaste remain. Measuring alluvial water quality at the mouth of the gulch will allow anassessment of the relative contribution of metals the shallow groundwater in this drainageis contributing to the NPL Site. Monitoring well HM1TMW-4 is located at the mouth, ofStray Horse Gulch and will be monitored in June for water level and changes in waterquality.

Area I - Upper California Gulch

Groundwater monitoring will occur at the mouth of Upper California Gulch to assesswater quality trends in the alluvium. Measuring alluvial water quality at the mouth of thegulch will allow an assessment of the relative contribution of metals the shallowgroundwater in this drainage is contributing to the Lower California Gulch Alluvium.


Monitoring well NW-1 is located at the mouth of Upper California Gulch and will bemonitored in the spring or summer for water level and changes in water quality.

4.0 FIELD SAMPLING PLANt>

Sampling described in this Work Plan will be performed according to the methods andprocedures specified in existing documents and applicable Standard OperatingProcedures presented in the Compendium of Standard Operating Procedures (EPA,1996).

5.0 DATA MANAGEMENT, TRANSMITTAL AND REPORTING

To be determined - see Section 1.3, Responsibilities.


6.0 REFERENCES

CDPHE, 2001. Letter to Mr. Stan Christensen, EPA. Subject: Cal Gulch Operable Unit12 Final Draft Remedial Action Objectives, Cal Gulch Superfund Site, Leadville,Colorado.

MFG, Inc. 2001. Data Transmittal for 2000 Surface Water and Groundwater Monitoring,Apache Tailing Impoundments and Yak Tunnel Surge Pond, California Gulch Site,Leadville, Colorado. March.

RMC, 2000. California Gulch Superfund Site, Site-Wide Groundwater Sampling,Summer 2000. October.

RMC, 2001. California Gulch Superfund Site, Site-Wide Groundwater Sampling,Summer 2001. October.

URS, 2002. 2001 Groundwater Sampling and Analysis Report, Upper Arkansas RiverFluvial Tailings, Lake County, Colorado. February 8.

U.S. Environmental Protection Agency (EPA), 1996. "Compendium of StandardOperating Procedures for the California Gulch CERCLA Site, Leadville, Colorado."EPA-4800-040-162. April

MFG, Inc., 1998. Evaluation of Rising Groundwater Levels Near Leadville, Colorado.

U.S. Environmental Protection Agency (EPA), 2002a Groundwater Hydrology In TheVicinity Of The Leadville Mine Drainage Tunnel and Operable Unit 6

U.S. Environmental Protection Agency (EPA), 2002b. Groundwater Sampling andAnalysis Report, Upper Arkansas Fiver Fluvial Tailings, Lake County, Colorado

TABLES

Table 1Groundwater Maintenance Summary

-

ASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOASARCOCDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHE .CDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHECDPHE .ZDTHE ~RessureclionRessurectionRessurection

AP1TMW-1AP1TMW11DAP1TMW11SAP1TMW12DAP1TMW12SAP1TMW14SAP1TMW16SAP1TMW-17AP1TMW18AP1TMW23NW5ANW5CNW5DP34RAP1PZ19AP1PZ21WCCPZIW01W03BBW-1BBW-2BBW-3BBW-4BBW-7BBW-10ABW-2ABW-4ADELAIDE- 1AP1TMW-1AP1TMW17BMW-1BMW-2BMW-3B-MGMW-2B-MGMW-3B-MGMW-4B-MGMW-5C5^1TMW-7ADW-10HIGHLAND MARY -1HM1TMW-3HM1TMW-4HM1TMW-5MA1TMW-1MA1TMW-2MA1TMW-3MA1TMW-4MIKADOS-1MW-19NW5ANW5CNW-10NW-13ANW-14OG1TMW-3PYRENESS-1PZ-4PZ-6PZ-10RAM-2WMW-1WMW-2WMW-3WMW-4CZ1TMW-7ANW-1OG1TMW-3

Hi / Low FlowHi / Low FlowHi / Low Flow

L Hi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low FlowHi / Low Flow

Every 5 yearsEvery 5 yearsEvery 5 yearsEvery 5 yearsEvery 5 yearsEvery 5 years

Annually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually"- JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JulyAnnually - JujyAnnually - JulyAnnually - July

1

(

Common Ions / MetalsCommon Ions / MetalsCommon Ions / MetalsCommon Ions / MetalsCommon Ions / MetalsCommon Ions / Metals

Field Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chetristry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/Metals _. _Field Parameters /Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet Chemistry/Major Cations/MetalsField Parameters/Wet _Ch,emLsJry/Major,.CalionsZMetals-Field Parameters/Wet Cherristry/Major Cations/MetalsField Parameters/Wet Cherr.istry/Major Cations/Metals

Annually - July Field Parameters/Wet Cnerr.istry/Major Latvons/Metals

__ _.-,..-,—

Table 2Laboratory Analyte List

Parameter

PHConductivityTotal Dissolved SolidsAlkalinitySulfateChlorideCalcium (dissolved)Sodium (dissolved)Magnesium (dissolved)Potassium (dissolved)

EPA Method

150.0120.1160.1310.1375.3325.2200.7200.7200.7200.7

MDL1

0.11.0

10.01.04.01

0.20.30.20.3 ,

ReportingUnits

std. unitsHmhos/cm

mg/Lmg/Lmg/Lmg/Lmg/Lmg/Lmg/Lmg/L

HoldingTime

24 hours28 days7 days14 days14 days14 days

6 months6 months6 months6 months

Metals (dissolved)AluminumCadmiumCopperLeadZinc

200.7 ICP200.8 ICP-MS

200.7 ICP200.8 ICP-MS

200.7 ICP

0.030.00050.0010.0010.01

mg/Lmg/Lmg/Lmg/Lmg/L

6 months6 months6 months6 months6 months

Notes:1 MDL = Method Detection Limit.

Table 3Groundwater Monitoring Plan Summary

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iiJ$S8

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SlliiWt

New Bedrock Well

New Alluvial Well

PZ-10/BMW-3

Robert Emmett ShaftPotential New Wells(2)

NW-5A

NW-5C

Potential New WellPair

SPR-23

Valentine Shaft

NW-8

NW-11

NW-13A

NW-15

NW-14

UMW-01

UMW-19

AP1TMW-23

OG1TMW-3

HM1TMW-4

NW-1

v-:̂ y';-S43 .̂i:v;i:S ;̂ ;

iSPWMSIn Pendry systemproximal to LMDTAdjacent to new bedrockwell

Well pair west of N. Stan-Ditch

Strav Horse Gulch

Advanced into LMDTAlluvial well east ofApacheBedrock well east ofApacheBetween Area B and AreaC along Pendery

Gaw Shaft

Valentine ShaftNorth of Cal Gulch, eastofLWTPSouth of Cal Gulch, southofCZLSite

Soi'th of Cal GulchSouth of Cal Gulch, SWofLeadvilleEast of Arkansas, belowCal GulchNear Arkansas, south ofCal GulchSear confluence ofArkansas and Cal Gulch

Oowngradient of Apache

Oregon Gulch

Stray Horse Gulch

Upper California Gulch

--,--: .,-.-• MonitorinSampling lorvLab

April/October

April/October

NA

NA

April/October

April/Octooer

April/October

April/October

NA

NA

June

June

June

June

June

June

June

April/October

Spring or Summer

June

Spring or Summer

e Frequency ;. -.-.Monitoring for. Field.•V? ̂ Parameters"^;

April/J une/ AugustOctober

April/June/AugustOctober







April/June/ AugustOctober


June

June

June

June

June

June

June

April/October

Spring or Summer

June

Spring or Summer

lv i-'£>'Sl*'ii}^

Parameters

Full Suite

Full Suite

None

None

Full Suite

Full suite

Full Suite

Full Suite

None

None

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

Full Suite

.'•-'/.V'^-'i'-'t-- S"1-'* •---^•- ••••*•'••••• -.,3.'* --.-•vO-sJC -" .S î-VS;—-:/! "- •f*^f ••-•".'-•'r">\' *';••;

f̂tfî |̂ slS;S?pH, specific cond., temp, waterlevel.pH, specific cond., temp, waterlevel.

water levels until replacementwells installed

pH. specific cond., water level.pH, specific cond., temp, waterlevel.pH, specific cond., temp, waterlevel. . .pH, specific cond., temp, waterlevel.pH, specific cond., temp, waterlevel.

Sote presence/absence of flow,pH. specific cond..Sole presence/absence of flow,pH. specific cond..?H, specific cond., temp, waterlevel.}H, specific cond., temp, waterevel.)H, specific cond., temp, waterevel.)H, specific cond., temp, waterevel.sH, specific_cond., temp, waterevel.

pH, specific cond., temp, waterevel.?H, specific cond., temp, waterevel.)H, specific cond., temp, waterevel.)H, specific cond., temp, waterevel.

pH, specific cond., temp, waterevel.

pH, specific cond., temp, waterevel.

1 - See Table 2 for list of analytical parameters

Table 4Well Information Summary

.,Cal GiijclKfl)l''"4'.' • >'-'A' •

New Bedrock Wells NA NA NA NA NA NA NA NA NANew Alluvial Well NA NA NA NA NA NA NA NA NANew LMDT Wells NA NA NA NA NA NA NA NA NANW5A 1985-2001 ND-S84 4.87-8.61 15-35 10114.23 10112.76 37 NA A.'luvial well, downgradicm of Yak WTP, upgradient of Apache TailingsNW5C 1984-2001 ND-78.6 7.19-8.46 48.0-108.0 10115.13 NA 113 NA Bedrock well, downgradient of Yak WTP, upgradient of Apache TailingsSPR23(Gaw) NA NA NA NA NA NA NA NA NAValentine NA NA NA NA NA NA NA NA NANWS 1984-1994 15.33-31.4 5.3-9.5 16-53 9746.34 9743.99 53 25 (north) NANWII 1984-1994 ND-0.3 13.3-16.9 25-55 9816.24 9814.07 55 lUO(soulli) NANWI3A 1984-2001 29.8-55 16.13 14.5-25 9622.27 9619.69 25 ISO(soulli) Alluvial well, lower California Gulch, 0.5 miles upgradiciU of ArkansasUMW01 1998-2001 NA 7.6-9.99 NA NA NA NA NA URS fluvial tailings well near Arkansas, downgradienl of Cal GulchUMWI9 1999-2001 NA 3.71-9.51 NA NA NA NA NA URS fluvial lulling well near confluence of Cal Gulch and ArkansasNW-14 1984-1985 0.57-1.83 6-15 10-50 9530.49 9527.57 50 NA East of Arkansas below California Gulch, near trailer parkAPITMW-23 5/21/2001 221 NA NA NA NA NA NA Just downgradienl of Apache TailingsOGITMW-3 1994-2001 525-1090 5.07 9.2-19.2 10081.93 10080.92 19.6 1200 (south) Perched aquifer well, downgradienl of Oregon GulchHM1TMW-4 1999-2001 ND-0.02 130.3 130.7-140.7 10307.68 NA 143.6 NA Alluvial well downgradienl of Hamm's Mill

I NW-1 1994-2000 168-868 NA 5-22 10340.47 10338.39 22 Upper California Gulch, upgradienl of Yak Portal

NA- Not Available

FIGURES

• B-MGMW-4r-»B Î̂ iftU-4—, •B-MGMW.2

NOTES:

1. Figure adapted from CIS Database provided byUSEPA Region 8. LEGEND

• Groundwater Monitoring Well

3000 6000 Feet

HDR Engineering, Inc.CURRENT AND HISTORIC

GROUNDWATER SAMPLING LOCATIONS

DRAFT FINAL OU12 GROUNDWATERMONITORING PLAN

| FIGURE 1DATE: NOVEMBER, 2002

Leadville Mine Drainage \

NOTES:

1. Figure adapted from CIS Database provided byUSEPA Region 8.

o I)61*|5 LEGEND

• Alluvial Well

° Bedrock Well

A Mine Shaft

3000 3000 6000 Feet

KR HDR Engineering, Inc.GROUNDWATER MONITORING LOCATIONS!

DRAFT FINAL OU12 GROUNDWATERMONITORING PLAN

DATE: NOVEMBER, 2002 FIGURE 2

DRAFT FINAL MONITORING PLAN FOR SITE-WIDE ...Draft Final Site-Wide Groundwater Monitoring Plan Operable Unit 12 - California Gulch NPL Site Pagel 1.0 INTRODUCTION This Groundwater

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