Golder Associates Inc. 200 Union Boulevard, Suite 500 Lakewood, CO USA 80228 Telephone (303) 980-0540 Fax (303) 985-2080

APACHE TAILINGS IMPOUNDMENT DEWATERING TREATABILITY STUDY WORK PLAN CALIFORNIA GULCH SUPERFUND SITE LEADVILLE, COLORADO

Prepared For: Asarco Incorporated 495 East 51st Avenue Denver, Colorado 80216-2098

Prepared By: Golder Associates Inc. 200 Union Blvd., Suite 500 Lakewood, Colorado 80228

Revised September 1995 943-2819

OFFICES IN AUSTRALIA, CANADA, GERMAfil?M$HI<£989Ste8«ft/EDEN, UNITED KINGDOM, UNITED STATES September 1995______TOC-i______943-2819 TABLE OF CONTENTS PAGE 1.0 INTRODUCTION...... 1 1.1 Purpose and Scope...... 1 1.2 Report Organization ...... 2 2.0 SITE CHARACTERIZATION ...... 1 2.1 General Site Description ...... 1 2.1.1 General Site Setting...... ! 2.1.2 General Hydrogeologic Setting...... 1 2.1.3 General Hydrologic Setting ...... 2 2.2 Existing Conditions at Apache Tailing Impoundments...... 2 2.2.1 Surface Features...... 2 2.2.2 Hydrology ...... 6 2.2.3 Historical Tailings Emplacement Method...... 6 2.3 Sampling Activities and Resulting Data for the Apache Tailing Impoundments...... 8 2.3.1 Data Collection Activities ...... 8 2.3.2 Hydrogeologic Results and Interpretation ...... 10 2.3.2.1 Lithologic Descriptions and Groundwater Elevations...... 11 2.3.3 Geotechnical Results and Interpretation...... 13 2.3.4 Nature and Extent of Contamination...... 15 3.0 IDENTIFICATION OF TREATMENT OBJECTIVES...... 1 3.1 Site Conditions that Justify Treatment...... 1 3.2 Determination of Treatment Scope ...... 1 3.3 Determination of Treatment Schedule...... 2 4.0 PROPOSED REMEDIAL TREATMENT TECHNOLOGY...... 1 4.1 Alternative Technologies Considered ...... 1 4.2 Description of Selected Treatment Technology ...... 2 4.2.1 Design of Ponded Water Removal System ...... 3 4.2.2 Design of Horizontal Dram System...... 3 4.3 Installation and Start-up Activities...... 5 Golder Associates September 1995______TOC-ii______943-2819 4.3.1 Ponded Water Removal System ...... 5 4.3.2 Horizontal Drain System...... 6 4.4 Operation and Maintenance...... 7 4.4.1 Ponded Water Removal System ...... 7 4.4.2 Horizontal Drain System...... 7 4.5 Data Collection and Management...... 8 4.5.1 Ponded Water Removal System ...... 8 4.5.2 Horizontal Drain System...... 8 4.5.3 Reporting ...... 9 4.6 Schedule for Implementation ...... 9 5.0 RESIDUALS MANAGEMENT...... 1 5.1 Removal...... 1 5.2 Storage...... ! 5.3 Disposal...... 2 6.0 HEALTH AND SAFETY...... 1 7.0 OTHER ISSUES RELATED TO PROPOSED ACTIVITIES...... 1 7.1 Access ...... 1 7.2 Cultural Resources ...... 1 7.3 Hazardous Materials Transportation Act...... 2 7.4 Colorado Noise Abatement Act...... 2 8.0 REFERENCES...... 1

LIST OF TABLES Table 2-1 Apache Tailings Impoundment Surface Water Sampling Field Data Summary Table 2-2 Apache Tailings Impoundment Test Hole Drilling Summary Table 2-3 Apache Tailings Impoundment Monitoring Well Completion Summary Table 2-4 Hydraulic Gradients and Groundwater Flow Directions, California Gulch Site Tailings Areas Table 2-5 Estimates of Aquifer Flow Parameters, California Gulch Site Tailings Areas Table 2-6 Apache Tailings Impoundment Geotechnical Testing Summary Table 2-7 Apache Tailings Impoundment Geotechnical Laboratory Data Summary Table 2-8 Apache Tailings Impoundment Groundwater Sampling Results Golder Associates September 1995 TOC-iii 943-2819 TABLE OF CONTENTS - Continued LIST OF TABLES - Continued Table 2-9 Apache Tailings Impoundment Surface Water Sampling Results Table 2-10 Apache Tailings Impoundment Method 1312 Samples LIST OF FIGURES Figure 1-1 Site Location Map Figure 2-1 Apache Tailings Impoundments Site Plan Figure 2-2 Apache Tailings Impoundments Surface Tailings Sample Locations Figure 2-3 Apache Tailings Impoundments Cross-Sections Figure 2-4 Apache Tailings Area Alluvial Aquifer Groundwater Elevation Contour Map May 1992 Figure 2-5 Heavy Metals Concentrations in Groundwater, California Gulch Area Monitoring Wells, November 1991 through January 1992 Figure 2-6 Major Metals Concentrations in Groundwater, California Gulch Area Monitoring Wells, November 1991 through January 1992 Figure 2-7 Groundwater Quality Parameters, California Gulch Area Monitoring Wells, November 1991 through January 1992 Figure 3-1 Apache Tailings Impoundment Dewatering Treatability Study Flow Chart Figure 4-1 Approximate Layout for Preliminary Dewatering System Figure 4-2 Downslope Pipe Detail Figure 4-3 Typical Horizontal Drain-Pair Installation LIST OF APPENDICES Appendix A Drilling Logs and Geotechnical Testing Results Appendix B Master Sample Lists Appendix C Tailings Geochemistry Appendix D Groundwater Appendix E Pipe Chemical Resistance Information

Golder Associates September 1995______1-1______943-2819 1.0 INTRODUCTION

This document presents Asarco's Dewatering Treatability Study Work Plan (Work Plan) for the Apache Tailings Impoundment. The Apache Tailing Impoundments undergoing this evaluation are included in Asarco's Work Area Management Plan, Operable Unit (OU) 7 of the California Gulch Superfund Site, Leadville, Colorado (Figures 1-1 and 1-2). The Treatability Study to be performed pursuant to this Work Plan is designed to facilitate the implementation of a final remedy; however, it does not constitute the final remedy nor does it pre-determine the final remedy. As outlined in the "Guidance on Conducting Remedial Investigations and Feasibility Studies" (EPA, 1988), a treatability study is typically performed during the detailed analysis of alternatives phase to provide the data needed to fully evaluate the alternatives. In the case of the Apache Tailings Impoundments, information gathered from the Treatability Study will be utilized during preparation of those portions of the Feasibility Study alternatives evaluation that pertain to implementability; specifically, access and trafficability. For this Work Plan, discussion on the nature and extent of contamination at the Apache Tailing Impoundments is limited to information on groundwater quality within the actual tailings impoundment, surface water quality of the ponded water on top of the impoundment, and leaching characteristics of the tailings material, since these are the parameters which are pertinent to evaluating the dewatering of the Apache Tailing Impoundments. Other aspects of the proposed treatability study address only physical properties of the tailings, rather than chemical properties of the tailings or surrounding surface water and groundwater. 1.1 Purpose and Scope The Apache Tailing Impoundments are being addressed prior to a Record of Decision (ROD). The impoundments may be impacting groundwater as well as surface water in California Gulch; therefore, it is necessary to evaluate remedial alternatives for the impoundments which will be included in the forthcoming Apache Tailing Impoundments Feasibility Study. These alternatives include: no action, institutional controls, containment (covering and surface water controls), and removal and transport of the tailings to the Oregon Gulch Tailings Impoundment or another on- Golder Associates September 1995______1-2______943-2819 site repository. However, prior to implementing any alternative with the exception of institutional controls or no action, the impoundments require dewatering, as much as possible, to allow access and facilitate easier handling of the tailing material. Therefore, to expedite the remediation process, this Work Plan addresses the treatment activities proposed to dewater the main Apache Tailing Impoundment. The main objective of this Work Plan is to: identify appropriate treatment options for dewatering of the tailing impoundment; select the most appropriate dewatering treatment option; and describe hi detail the proposed dewatering treatment technology and how it will be implemented. The Apache Tailing Impoundments are comprised of three (3) separate impoundments located within California Gulch at the southern boundary of the City of Leadville. The site consists of a main impoundment of about 11.3 acres, and two smaller impoundments downhill of the main impoundment. The smaller impoundments, known as Tailings Pond No. 2 and Tailings Pond No. 3, are approximately 1.5 and 0.5 acres, respectively. The Remedial Investigation (RI) of the impoundments was performed in the Fall of 1991 according to the Tailing Disposal Area Remedial Investigation Work Plan. Geotechnical tests performed during the RI indicated low bearing capacity, high water content tailing material over a significant portion of the main impoundment. Vehicular access on this material was, and is, extremely difficult. This Work Plan addresses only the main tailing impoundment as it is the only one which will likely present significant problems during remedial activities. The smaller impoundments exhibited good bearing capacity and trafficability during the remedial investigation. There are two sources of water at the main impoundment which are addressed hi the Work Plan: ponded water on the surface of the impoundment, and pore water contained within the actual tailings pile. 1.2 Report Organization This document has been prepared in general accordance with the Treatability Study guidance (Section 5.0) of EPA OSWER Directive 9355.3-01, "Guidance for Conducting Remedial Colder Associates September 1995______1-3______943-2819 Investigations and Feasibility Studies Under CERCLA" (EPA, 1988). Section 2 characterizes the site by describing the setting, history of Leadville, climate, geology, hydrogeology, and hydrology. Also discussed in Section 2 are summaries of past investigations conducted on the Apache Tailing Impoundments, including an overview of the pertinent sampling results from the Tailings RI activities at the Apache Tailing Impoundments. Section 3 presents the treatment justification, scope, and schedule. Section 4 discusses the various treatment technologies considered and details the proposed treatment technology, including installation, operation, maintenance, and data collection. Section 5 describes how the residuals from the treatment operation will be managed, and Section 6 outlines health and safety procedures to be followed. Section 7 discusses other issues related to the proposed activities. The references are found in Section 8.

Colder Associates August 1995______2-1______943-2819 2.0 SITE CHARACTERIZATION

This section summarizes the Apache Tailings site, including the physical and geotechnical background information on the main impoundment. The site characterization information is primarily taken from the Tailings Disposal Area Remedial Investigation Report, California Gulch Site (Asarco, 1994).

2.1 General Site Description 2.1.1 General Site Setting

The California Gulch Site is located in Lake County, Colorado in the upper Arkansas River watershed, approximately 100 miles southwest of Denver, Colorado (Figure 1-1). The site includes the towns of Leadville and Stringtown, and the confluence of the Arkansas River and California Gulch. Elevations at the site range from 9,570 feet above Mean Sea Level (MSL) at the confluence to 12,250 feet above MSL. Tailings in the Leadville area are the waste products resulting from the milling and processing of mineral ores. The tailings were typically slurried to tailings ponds such as the Apache Tailings Impoundments. 2.1.2 General Hydrogeologic Setting Groundwater in California Gulch, occurs in both bedrock and alluvial aquifers. Recharge to the bedrock and alluvial aquifers in the California Gulch area results from direct infiltration of precipitation and surface water, including snowmelt. Observed fluctuations in the water table indicate that recharge occurs principally during the snowmelt and that short-duration summer thunderstorms are of little consequence (Turk and Taylor, 1979). The nature of groundwater and surface water interaction hi the top 10 feet of the alluvial aquifer was explored by EPA by installing 40 temporary shallow piezometers (EPA, 1987a). Their results indicated that upper California Gulch, in general, is gaming from the bedrock aquifer and Colder Associates September 1995______2-2______943-2819 the lower gulch is losing to the alluvial aquifer (EPA, 1987a). The distribution and extent of infiltration from the gaining or losing zones appeared to vary over time, and surface streams appeared to act as a recharge source to the aquifer during spring snowmelt, when surface water levels are high (EPA, 1989). The groundwater/surface water interaction is discussed in detail in the Hydrogeologic Remedial Investigation Report.

2.1.3 General Hydrologic Setting California Gulch drains approximately 11.5 square miles and discharges into the Arkansas River. The mainstream of California Gulch receives water from several ephemeral drainages, including Stray Horse Gulch, upper California Gulch, Oregon Gulch, Georgia Gulch, Pawnee Gulch, Airport Gulch, and Malta Gulch. It also receives discharges from the Yak Tunnel Water Treatment Plant (WTP) and the Leadville Sewage Treatment Plant. Further characterization of the surface water regime in the California Gulch area is presented in the Surface Water Remedial Investigation Report.

2.2 Existing Conditions at Apache Tailing Impoundments

The following section details the physical features and characterization of the hydrology and hydrogeology specifically in the vicinity of the Apache Tailings Impoundment at the time of the remedial field investigation.

2.2.1 Surface Features The Apache Tailings Impoundment consists of a main tailings impoundment and two smaller tailings impoundments located in California Gulch, approximately 1,500 feet downhill of the Yak Tunnel Operable Unit Surge Pond, as illustrated on Figure 2-1. California Gulch is approximately 600 feet wide and slopes approximately four percent to the west in the Apache Tailings area. The main impoundment is the furthest to the east and extends across the gulch. The two smaller impoundments, Tailings Pond No. 2 and Tailings Pond No. 3, are located west Colder Associates September 1995______2-3______943-2819 and downhill of the main impoundment and directly north and adjacent to water flowing in the gulch. Several mill buildings are located at the northeast corner of the main impoundment and approximately 150 feet south of U.S. Highway 24. The mill reprocessed tailings from the main impoundment and deposited the byproducts into Tailings Ponds No. 2 and No. 3. The closest home is located approximately 300 feet west of the mill along the Highway 24 access road, 100 feet north of Tailings Pond No. 2. Another residence is located approximately 400 feet east of the main impoundment. Several other residences and businesses are within 300 feet of the main impoundment at the southern boundary of Leadville. A control fence crosses California Gulch near the base of the Surge Pond embankment and separates the Yak Tunnel Operable Unit from the upgradient side of the impoundment area. California Gulch and the impoundment can be accessed from both the upgradient and downgradient sides. The upgradient side is accessed by a gravel road which passes through the Denver-Salida-Leadville cargo transfer yard to the north of the tailings impoundments. This road leads to the northeast comer of the main impoundment. The gulch and downstream toe of the maui impoundment embankment can be accessed by an old railroad grade that branches off the county landfill road.

Surface water flow hi California Gulch is presently routed from the Water Treatment Plant around the main impoundment through the California Gulch channel (Figures 2-1 and 2-2). The ditch intersects the southern edge of the impoundment where the flow is then routed through two 24-inch diameter clay tile pipe culverts, designated the California Gulch/Apache Tailings Diversion culverts. These historic culverts were installed because the ditch invert is below the top surface of the main impoundment. The current condition of the culverts is unknown.

2.2.1.1 Main Impoundment The main impoundment covers an area of approximately 11.3 acres. Embankment slopes range from 1.5:1 (H:V) to 1.75:1, and on the south embankment approach 1:1. Embankments range hi height from approximately 15 feet on the north and east to 50 feet on the south. Materials on Colder Associates September 1995______2-4______943-2819 the embankment surface typically consist of medium- to coarse-grained sands. These materials have bonded together to form a hard crust approximately '/2-to one-inch thick. The volume of tailings in the mam impoundment is estimated at approximately 630,000 cubic yards based on data from the drilling program. Vegetation is not present on the main impoundment. Remnants of elevated open troughs constructed of wood are evident on the top surface of the impoundment and the embankment faces. These structures were a gravity system that carried tailings from the mill to the impoundment, where tailings were spigotted from the embankment towards the center of the impoundment judging from the location of the wooden troughs. No evidence of decant or dewatering systems was observed on the impoundment surface.

The main impoundment has an existing perimeter berm on the top surface ranging from 1A to approximately three feet hi height. The berm prevents accumulated surface water from leaving the surface of the impoundment. Surface tailings are generally oxidized and exhibit a wide variety of colors including white, tan, brown, green, and yellow, although a majority of the surface is orange and red. Areas on the northern side of the impoundment and away from the pond are relatively soft or loose and exhibit low bearing capacity based on difficulties associated with vehicle access. This section of the impoundment surface is characterized by raised and unconsolidated mounds of tailings approximately one to two feet hi height and three to ten feet in diameter. Surface tailings hi these areas consist of silt and fine-grained sands. The bearing capacity of the surface increases closer to the pond. The only vehicle that successfully accessed the surface during the field investigation was a low ground pressure track-mounted drill (Asarco, 1994).

The top surface of the main impoundment slopes at approximately five percent from the perimeter berm toward the center of the impoundment. Precipitation pools on the surface near the southern edge of the impoundment. The pool remains throughout the year, although size fluctuates. Although not typically observed, the pond has the potential to increase in size enough to overflow the western embankment during periods of intense and/or extended precipitation. Activities associated with the mill have removed significant quantities of berm materials allowing

Colder Associates September 1995______2-5______943-2819 the pond to overflow. Overflow travels down the access ramp toward the mill, is diverted by a drainage ditch approximately 20 feet south of the mill, and is routed to Tailings Pond No. 2.

The water ponded on the main impoundment surface measured approximately 375 feet in length and varied in width from 30 to 130 feet. The volume of water was estimated assuming that cross-sections of the ponded water were trapezoidal with maximum and average depths of one foot and 0.75 feet, respectively. The width of the ponded water was measured every 30 yards along the length. The area and volume of the ponded water were estimated on September 17, 1991 at approximately 0.67 acres and 1A acre-feet (163,000 gallons), respectively.

Several small tailings embankment slope failures have occurred on the south side of the main impoundment. The failures are located between the outlet of the California Gulch/Apache Tailings Diversion culverts and a seep/spring area near the toe of the embankment. The failures extend over the entire height of the embankment and are approximately five to 10 feet deep, as measured perpendicular to the original slope surface. It is unknown how many failures exist or when the failures occurred. Materials on the exposed failure surfaces have bonded to form a crust approximately %-to one- inch deep. The embankment failures do not appear to be a threat to the integrity of the impoundment. The outlet for ponded water on the west side of the impoundment is considerably lower than the lowest portion of the embankment near the failure areas; therefore, as the pond size increases, it overflows the west embankment long before it approaches the south embankment.

2.2.1.2 Tailings Pond No. 2

Tailings Pond No. 2 is located immediately west of the main impoundment and covers an area of approximately l!/2 acres. Vegetation does not exist on Pond No. 2. Impoundment berms for Pond No. 2 were constructed of alluvial materials from California Gulch. The berms range from 1:1 (H:V) to 1.5:1, are approximately 10 feet in height, and are approximately 10 feet wide at the top. Upstream containment for Tailings Pond No. 2 is provided by the main impoundment. Several feet of freeboard (capacity) remains in the No. 2 impoundment. Ponded water is present Colder Associates September 1995______2-6______943-2819 on the surface of the No. 2 impoundment during periods of intense and/or extended precipitation; however, it appears to be dry the majority of the year. There is no evidence of engineered outlets or overtopping at Pond No. 2. The tailings for Pond No. 2 in test hole AP2B1 were approximately 9 feet thick and ranged from silt to sandy silt. The reprocessed materials in the No. 2 impoundment are very fine grained and exhibit desiccation cracking upon drying. The bearing capacity of materials hi the No. 2 impoundment is relatively high based on ease of vehicle access.

2.2.2 Hydrology

Surface water flow in California Gulch has historically been near the center of the gulch, beneath what would now be the approximate center of the main impoundment. Currently, the flow above the Apache Tailings Impoundment is carried by clay tile pipes beneath the impoundment on the west side. A wooden box culvert was constructed at the toe of the east embankment, apparently to convey surface water underneath the impoundment. Current condition of the box culvert is unknown. These pipes and culverts are not included in the scope of the Treatability Study.

2.2.3 Historical Tailings Emplacement Method Observations of the embankment and surface conditions coupled with information collected during the drilling and sampling work task suggest that the main impoundment was constructed utilizing the "upstream" method. The following paragraphs discuss in detail the upstream construction method that appears to have been used at the main impoundment.

Tailings were probably delivered to the impoundment from the mill hi slurry form through a pipeline or open wooden trough. Some form of starter dike was erected, although it appears that the starter dike was not constructed of alluvial material, as evidence of such a structure was not located during the field investigations. Rather, a small starter dike may have been constructed of previously deposited tailings to initiate the embankment construction, and tailings were spigotted upstream from the crest of the dike. The impoundment created by the starter dike contained the Golder Associates September 1995______2-7______943-2819 tailings and residual water from the slurry discharge. The coarse fraction (sands) in the tailings slurry settled out near the embankment, forming a beach, and the fine fraction (silts and clays) in the tailings slurry settled out in the ponded water, usually wherever the low spot was at the time of deposition. This low spot, or pond, changed locations within the impoundment depending on the spigotting locations and percentage of coarse and fine fractions in the tailings. Tailings were discharged from different areas along the embankment to uniformly increase height of the beach/embankment and move the pond to the desired area of the impoundment. As the embankments expanded, the slurry discharge locations were probably maintained near the top of the embankment and moved gradually upstream.

The main impoundment surface slopes toward the center from all directions, except from the west where reprocessing activities have removed a significant portion of the embankment. A pond still exists on the surface. During the operation of a typical tailings impoundment, residual water and/or water from precipitation on the pond must be removed to prevent overtopping of the embankments. No evidence that decant towers were used during operation of the main impoundment exists; therefore, water was either recycled to the mill or discharged over the embankment to California Gulch. Evidence of an outlet on the downgradient (west) side of the impoundment may have been destroyed by the reprocessing activities, and there is no evidence of outlets on any of the other intact embankments.

The hardened or cemented behavior of the surface tailings at some locations is believed to be the result of complex oxidation processes involving various mineral constituents. The chemical alteration on the embankments has hi effect "armored" the surface and reduced erosion. The failures on the southern embankment may have occurred due to the steepness of the embankment hi conjunction with undercutting of the embankment from flow in California Gulch exiting the California Gulch/Apache Tailings Diversion culverts.

Golder Associates September 1995______2-8______943-2819 2.3 Sampling Activities and Resulting Data for the Apache Tailing Impoundments

The following sections summarize the relevant information pertaining to the physical and chemical sampling activities and resulting data obtained from previous investigations at the Apache Tailings Impoundments. Chemical analysis information, limited to the tailings monitoring well and ponded surface water, as well as tailings leach analysis results, are discussed.

2.3.1 Data Collection Activities

A field investigation of the Apache Tailing Impoundments was conducted in the Fall of 1991. The field investigation included geotechnical sampling of tailings (surface and subsurface) and determination of in-situ permeability. Surface tailings sample locations are shown on Figure 2-2. The following sections describe the pertinent portions of the data collection program in detail.

2.3.1.1 Surface Water Sampling

Sampling of surface water locations at the Apache Tailings Impoundment was performed in September, 1991. Surface water flow measurements were made at upgradient locations APUP and APU1 and downgradient location CG03. Ponded water on the surface of the tailings (APPD) was also sampled. Figure 2-1 displays the surface water sampling locations. Surface water discharge and field parameter measurements for the surface water sampling locations are presented in Table 2-1. Flow measurements will be discussed in more detail in the upcoming Feasibility Study for the Apache Tailings. 2.3.1.2 Drilling and Sampling of Test Holes As shown in Figure 2-1, a total of 13 test holes were drilled in and near the tailing disposal area as follows: AP1B1, AP1B2, and AP1B3 downgradient of the disposal area; AP1B7 upgradient of the disposal area; AP1B4 through AP1B6, and AP1B8 through AP1B11 in the main Golder Associates September 1995______2-9______943-2819 impoundment; AP2B1 in Tailings Pond No. 2; and AP3B1 in Tailings Pond No. 3. Table 2-2 provides a summary of test hole drilling information. Appendix A contains the surveyed state plane coordinates and elevations of the test holes and monitoring wells. Appendix B provides a list of all geotechnical samples and data collected during the drilling investigation. Appendix C contains a listing of all tailings samples collected for geochemical analysis.

2.3.1.3 Geotechnical Sampling Subsurface tailings and foundation soils samples were collected from all seven test holes in the main impoundment and from both test holes in the secondary impoundments. Representative samples of tailings materials from the main impoundment were selected for geotechnical laboratory analyses.

2.3.1.4 Monitoring Well Installation, Development. Sampling, and Water Level Measurement

A total of eight monitoring wells were completed at the following locations: AP1TMW8, AP1TMW9, and AP1TMW10 in the main impoundment; AP2TMW1 in Tailings Pond No. 2; AP1TMW7 upgradient of the main impoundment; and AP1TMW1, AP1TMW2, and AP1TMW3 downgradient of the disposal area. The monitoring well locations are shown on Figure 2-1. Monitoring well completion depths and screened intervals are summarized hi Table 2-3. Remaining test holes AP1B4, AP1B5, AP1B6, AP1B11, and AP3B1 were grouted throughout their depth with cement/bentonite grout, or with bentonite chips in cases where significant grout loss and/or caving conditions occurred. Appendix A contains information from field drilling logs and well completion logs. Monitoring well development data and reported field parameters measured at the conclusion of development are included hi Appendix D. Significant field observations and conditions encountered during drilling are presented hi Section 2.3.2.

Golder Associates September 1995______2-10______943-2819 Monthly measurement of groundwater levels began in January 1992 according to the Hydrogeologic Work Plan (Asarco, 1991). Groundwater level data collected to date from monitoring wells located in and near the Apache tailings impoundments is found in Appendix D.

2.3.1.5 In-Situ Permeability Testing of Monitoring Wells

Positive displacement (falling head) and negative displacement (recovery) slug tests were performed on monitoring wells AP1TMW1, AP1TMW3, and AP1TMW7. A recovery slug test was performed on AP1TMW9.

Slug test field data and calculated hydraulic conductivity values for both partially and fully screened aquifer conditions, which were estimated with the Bouwer and Rice (1976) and Bouwer (1989) method of analysis are presented in Appendix D.

2.3.2 Hydrogeologic Results and Interpretation

Hydrogeologic data collected during drilling of the eight monitoring wells, as well as slug testing and monthly water level monitoring, were used to characterize the hydrogeologic conditions beneath the Apache tailings area. Geologic cross-sections and groundwater elevation contour maps were constructed using this data to aid in the interpretation. Figure 2-3 presents hydrogeologic cross-sections of the disposal area. The cross-sections were developed using information contained in the respective summary logs and display the locations of selected upgradient and downgradient monitoring wells, measured water levels from these monitoring wells, and the general lithologic material types encountered. Appendix D presents groundwater level data collected from monitoring wells located in and near the impoundment, and a summary of the slug test field data and estimated hydraulic conductivity values calculated using the Bouwer and Rice (1976), Bouwer (1989), and Hvorslev (1951) methods of analysis.

Colder Associates September 1995______2-11______943-2819 2.3.2.1 Lithologic Descriptions and Groundwater Elevations As shown in Figure 2-3, monitoring wells AP1TMW1, AP1TMW2, and AP1TMW3 are located downgradient of the Apache Tailings impoundments in close proximity to California Gulch. These monitoring wells were completed in alluvial deposits consisting of sand, gravel, and cobbles.

Monitoring well AP1TMW7 is located approximately 400 feet east (upgradient) from the eastern edge of the main impoundment and 800 feet north of the California Gulch channel. Sediment deposits encountered during the drilling of monitoring well AP1TMW7 appeared to be poorly sorted glacial outwash material. Based on water levels measured in monitoring well AP1TMW9, located roughly in the center of the main impoundment, saturated conditions exist in the tailings located hi this region of the impoundment. Depth to water in monitoring well AP1TMW9 varied from approximately 19.4 feet bgs in February 1992 to 16.7 feet bgs in October 1992. The saturated conditions at this level occur just above an extensive clay (or fine fraction of tailings) layer encountered at the base of the coarse fraction of tailings. Recharge in the area of AP1TMW9 is from infiltration through the tailings surface. Alluvium was encountered hi this test hole at a depth of 32 feet below the tailings surface. The maui impoundment embankments appear to be unsaturated based on lithologic interpretation of borehole data and the lack of water hi the monitoring wells installed hi those areas. Monitoring well AP1TMW8 was completed in the southwest embankment of the main impoundment at a total depth of 35.5 feet. Alluvium was encountered hi this test hole at a depth of 45 feet. During drilling, minor layers of partially saturated tailings were encountered hi well AP1TMW8 from 31 to 47 feet (Figure 2-3), but no free water has been observed hi the well. Similar conditions were observed hi boring AP1B5 (Figure 2-3), which was drilled into the impoundment embankment approximately 225 feet southeast of well AP1TMW8. Monitoring well AP1TMW10 was installed to a depth of 19 feet and was completed hi the southeast Golder Associates September 1995______2-12______943-2819 embankment. Alluvium was encountered in the test hole at a depth of 26 feet. Both AP1TMW8 and AP1TMW10 have been dry since installation.

Monitoring well AP2TMW1 was completed in the tailings above the alluvium in Tailings Pond No. 2 and has been dry since installation. Total depth of the screened interval is seven feet and alluvium was encountered in the test hole at a depth of nine feet.

2.3.2.2 Groundwater Flow Directions and Hydraulic Gradients An alluvial aquifer groundwater elevation map for the Apache tailings area (Figure 2-4) was prepared using groundwater elevations measured in May 1992. The groundwater elevations were measured in Apache tailings impoundment monitoring wells (AP series) and EPA-installed monitoring wells (NW series). Review of monthly groundwater elevations measured in 1991 and 1992 (Appendix D) indicates only minor groundwater elevation fluctuations. The average groundwater flow direction and hydraulic gradient of the alluvial aquifer in the Apache tailings area were estimated graphically by triangulating the water level elevations at the positions of monitoring wells AP1TMW3, AP1TMW7, and NW-16, which are believed to be representative of the water table surface. The May 1992 groundwater hydraulic gradient and flow direction are shown in Figure 2-4. The triangular area bounded by these three wells covers most of the Apache tailings impoundment and part of California Gulch downgradient of the tailings (Figure 2-3). Average flow directions and hydraulic gradients for the alluvial aquifer in this area were estimated for May, June, and September of 1992 (Table 2-4). During these periods, groundwater flow direction was to the southwest, and hydraulic gradients ranged from 0.034 to 0.035 foot/foot. As shown in Table 2-5, the estimated range of average groundwater linear velocities in the alluvial aquifer in the Apache tailings area is about 5 x 10"f\ to 140 feet/day. A locally restricted perched or mounded groundwater zone appears to occur within the main Apache tailings impoundment near monitoring well AP1TMW9 (see cross-section D-D', Figure Golder Associates September 1995______2-13______943-2819 2-3). The hydraulic gradient of the perched or mounded water cannot be estimated with the available information. It is expected that this zone is hydraulically connected to the underlying alluvial aquifer and that seepage from this zone occurs principally in a downward direction. 2.3.3 Geotechnical Results and Interpretation

The Apache Tailings Impoundment consists of three separate tailings impoundments. Figure 2-3 presents several geotechnical cross-sections of the three tailings impoundments. The cross-sections were constructed using information contained in the respective summary logs and display pertinent test hole and monitoring well information, water levels from these monitoring wells, and general lithologic materials encountered. The following sections discuss materials encountered during the subsurface drilling and sampling program, geotechnical testing of selected samples, and current conditions of the impoundments.

2.3.3.1 Drilling. Sampling, and Testing

The main impoundment contains tailings ranging from coarse-grained sands to silts and clays. A majority of the materials encountered within the impoundment and below a depth of approximately five feet were moist to saturated. Several lithologies were encountered during drilling of the main impoundment, included silt, fine to coarse sand, and low to high plasticity clay. It was not determined during drilling and sampling whether the variation in material types resulted from discrete and separate time periods of tailings disposal, from a change in ore types, or from a change in milling procedures. The clayey material varied in thickness from 7.5 feet in AP1B9 near the center of the impoundment to 0.1 of a foot in AP1B6 in the northeast corner of the impoundment, and was not located on the exposed embankment surfaces. Test holes located near the edges of the impoundment (AP1B4, AP1B5, AP1B6, AP1B8, and AP1B10) contained significant quantities of the sandy embankment material type. Sample locations and methods, and testing data collected during drilling are contained hi the summary logs in Appendix A. Golder Associates September 1995______2-14______943-2819 Tailings consistency based on Standard Penetration Test (SPT) blow counts was typically loose to medium dense with occasional zones of very loose material. The underlying alluvium tested as medium dense to dense with occasional zones of loose material.

Geotechnical analysis were performed on several samples for classification and characterization purposes. Samples selected for testing are summarized in Table 2-6. Complete test results are summarized in Table 2-7. Data plots are presented in Appendix A. Sieve analyses were conducted on 21 tailings samples from the main impoundment. The percent fines, or percent passing the No. 200 sieve (0.074 mm) ranged from 11 percent to 100 percent. Hydrometer analyses were performed on 15 of the finer-grained samples. Atterberg limits tests were conducted on eight fine-grained tailings samples. Liquid limits and plasticity indexes ranged from 19 to 45 and from 2 to 20, respectively, with one sample classified as non-plastic. According to the Unified Soil Classification System (USCS) and Casagrande's plasticity chart, the samples were generally low-plasticity silts and clays (ML, CL, or CL-ML classification). Moisture contents were measured on 21 tailings samples. Moisture contents ranged from 2.1 percent to 48.2 percent.

Specific gravity tests were performed on 13 tailings samples from the main impoundment. The specific gravity values ranged from 2.48 to 3.42. A consolidation test was performed on one tailings sample. The test was conducted with five load increments. The sample yielded a compression index (C) value of 0.38 and the coefficient of consolidation (c) ranged from 0.026 2 c v to 0.13 in/min. Data from the consolidation of triaxial samples yielded cv values ranging from 0.017 to 0.476 in2/min. Permeability tests were conducted on two tailings samples. Permeability values from the tests were 7.0 x 10"7 and 8.2 x 10"7 cm/sec (2.0 x 10"3 and 2.3 x 10'3 ft/day). A direct shear test was conducted on one tailings sample from the main impoundment. The resulting shear strength value was 30 degrees with no cohesion. Triaxial tests were conducted on three tailings samples. Effective friction values ranged from 24.2 to 30.9 degrees, and effective Colder Associates September 1995______2-15______943-2819 cohesion values ranged from 1.4 to 5.4 psi, using the maximum deviator stress method. Strength values derived from the peak stress ratio method ranged from 28.7 to 34.7 degrees (effective friction angle) and 1.5 to 2.2 psi (effective cohesion).

2.3.4 Nature and Extent of Contamination For this treatability study work plan, discussion on the nature and extent of contamination at the Apache Tailing Impoundments is limited to information on groundwater quality within the actual tailings impoundment, surface water quality of the ponded water on top of the impoundment, and leaching characteristics of the tailings material, since these are the parameters which are pertinent to evaluating the dewatering of the Apache Tailing Impoundment. Other aspects of the proposed treatability study address only physical properties of the tailings, rather than chemical properties of the tailings or surrounding surface water and groundwater.

2.3.4.1 Groundwater During the period from November 1991 through January 1992, groundwater was sampled from a series of tailings monitoring wells and alluvial background monitoring wells. The groundwater samples were analyzed for selected metals, major ions, and other chemical parameters. Specifically, the three groups of analytes were: (1) dissolved heavy metals including arsenic, cadmium, lead, and zinc; (2) dissolved major metals including aluminum, iron, and manganese; and (3) other water quality parameters including specific conductivity (field), dissolved sulfate, total dissolved solids (TDS), and pH (field). Three maps, one for each analyte group, were constructed to display the analytical results with respect to sample locations (Figures 2-5, 2-6, and 2-7). The nature and extent of contamination analyses hi the following sections are semi-quantitative interpretations based on the available analytical data. Metal concentrations and other water quality parameter ranges have been rounded off to two significant figures hi the text to facilitate comparisons. Golder Associates September 1995______2-16______943-2819 Results for the groundwater sample collected from monitoring well AP1TMW9, which is located within the tailings impoundment, indicate that several metal concentrations and other water quality parameters are above those in the upgradient well (Figures 2-5 through 2-7). The metal concentrations are zinc, 550 mg/1; iron, 32,000 mg/1; and manganese, 14,000 mg/1. Arsenic, cadmium, lead, and aluminum were not detected above CRDLs in this sample. Results for the water quality parameters include field-specific conductivity, 6,600 umhos; sulfate, 6,100 mg/L; IDS, 8,000; and field pH, 6.2 (Figure 2-7). Table 2-8 presents analytical results for the Apache Tailings monitoring wells. There are some substantial differences between the water quality of the perched or mounded zone in the tailings material and the downgradient wells. Most notably, these differences include the detection of cadmium and lead hi well AP1TMW1 and elevated concentrations of zinc, aluminum, iron, and manganese. The relationship of water quality data from the tailings impoundment well to those from the downgradient wells is not clear. The wide ranges of metals concentrations and other water quality parameters hi the downgradient wells may result from variations in the leachate plume or effects from California Gulch surface water. Additional groundwater interpretation is presented hi the Hydrogeologic RI Report.

2.3.4.2 Ponded Surface Water Sampling and analysis of the surface water ponded on the main Apache Tailings Impoundment was conducted during the RI for the same parameters used to evaluate groundwater. These include three groups of analytes: (1) dissolved heavy metals including arsenic, cadmium, lead, and zinc; (2) dissolved major metals including aluminum, iron, and manganese; and (3) other water quality parameters, including field specific conductivity, sulfate, total dissolved solids (TDS), and field pH. A sample of water ponded on the Apache tailings was collected at site APPD, shown on Figure 2-1. A summary of ponded surface water chemical analyses data is presented in Table 2-9.

Colder Associates September 1995______2-17______943-2819 It was not apparent, based on the locations and flow measurements at the sampling stations, that significant flow was being discharged from the main Apache Tailings pond during the sampling event. Additionally, it was unclear whether significant flow from surface water contact with the tailings area existed during the sampling event. Also, the ponded water sample from the Apache Tailings Impoundment revealed a low pH value of 1.7.

2.3.4.3 Method 1312 Results Method 1312 is a synthetic precipitation leaching test designed to simulate rainwater leaching of waste materials, and TCLP (Toxicity Characteristic Leaching Procedure) regulatory levels for leachates are used to determine whether the waste which produced the leachate exhibits the characteristics of a hazardous waste. Leachates from 3 of 42 subsurface tailings samples collected from the Apache Tailings Impoundment exceeded the regulatory limit of l.Omg/L (1,000 ug/L) for cadmium. Cadmium values exceeding the regulatory limit ranged from 1.02 to 7.09 mg/L. Results of Method 1312 analyses are shown in Table 2-10.

Colder Associates September 1995______3-1______943-2819 3.0 IDENTIFICATION OF TREATMENT OBJECTIVES

The following treatment objective has been established for the dewatering of the main impoundment at the Apache Tailings site:

Increase strength, stability, and trafficability of the tailings for future remedial activities, particularly along the southern slope near California Gulch. 3.1 Site Conditions that Justif Treatment

* The main Apache Tailing Impoundment material exhibits low shear strength and high water content, greatly inhibiting or preventing vehicle access and creating the potential for slopes to become unstable upon commencement of remedial activities; *• The main impoundment consistently contains ponded water that contributes to the poor consistency of the tailings; and, * Dewatering the tailings will facilitate future remedial activities. The implementation of a treatment action for the Apache Tailing Impoundments will alleviate the concerns indicated above. 3.2 Determination of Treatment Scope The objectives outlined above will be met by installing a two-part dewatering system in the main Apache Tailing Impoundment. Specifically, the scope of work encompasses the folio whig activities: minimizing ponded water on the tailings surface to reduce infiltration; and, providing a mechanism for removal of water contained within the low-permeability tailings. These activities will also promote drying and consolidation of the tailings to improve trafficability. The treatability study has been designed to be implemented in a phased manner to enable full utilization of knowledge gained as the treatment process progresses, as shown hi the flow chart on Figure 3-1. Golder Associates September 1995______3-2______943-2819 3.3 Determination of Treatment Schedule

Due to the climate in Leadville, it would likely be necessary to perform field activities associated with the proposed treatability study in the summer or fall. The dewatering systems will be installed in phases throughout a one-year period, with additional treatment components added as necessary based on observed field conditions and regular monitoring of the impoundment and water removal systems. Additional treatment components which may be considered include additional horizontal drains, vertical extraction points or test borings, and test trenches. Although the regular monitoring will enable continual assessment of the effectiveness of the dewatering systems, the treatability study should be conducted for at least 1 year prior to scheduled final remedial actions. At the end of the year, trends in impoundment water levels and outflow rates will be plotted, final results of the treatment activities will be evaluated, and a judgment made as to whether the tailings have been sufficiently dewatered prior to implementation of remedial activities.

Golder Associates September 1995______4-1______943-2819 4.0 PROPOSED REMEDIAL TREATMENT TECHNOLOGY

4.1 Alternative Technologies Considered

Based on the previous data collected on the tailing impoundments, and generally accepted engineering practices for dewatering of mine tailings, several treatment options were evaluated prior to preparing this Work Plan for the main Apache Tailing Impoundment. Two categories of options are presented, to address the ponded water as well as the perched or mounded water contained within the tailings. Ponded Water Options: PI. No Action leaves sources in their existing condition with no control or cleanup planned. This option does not meet the treatment objective; therefore it was eliminated from further consideration. P2. Removal of Ponded Water by Tanker Truck would consist of periodic removal of the ponded water directly from the surface of the impoundment using a tanker truck for removal and transport to the Yak Tunnel Water Treatment Plant for treatment. This option would not be desired because surface water would build up on the tailings surface between pumping events. P3. Removal of Ponded Water by Pipe or Channel to Holding Pond would continuously drain off any liquid collecting on the impoundment surface via downslope channel or pipe on the side of the impoundment emptying into Tailings Pond No. 2 or another holding area. A tanker truck would be used to transport the water from the holding pond to the WTP as needed. Perched Tailings Water Options:

Tl. No Action leaves sources hi then: existing condition with no control or cleanup planned. This option does not meet the treatment objective; therefore it was eliminated from further consideration. T2. Vertical Wells and Extraction Pumping System would involve installing a number of vertical wells designed to maximize inflow, and installing pumps to remove water from within the tailings. This option was eliminated because of the difficulty in accessing the tailings with a drill rig, the limited zone of Golder Associates September 1995______4-2______943-2819 influence of such wells, and the expense associated with the utilities and header network that would be required on top of the tailings to transport water extracted from the tailings. T3. Wick Drains would involve installation of numerous wick drains vertically into the tailings. This option was eliminated because wick drams require significant loading or surcharge on top of the strata to be dewatered. Access also may be a problem. T4. Drainage Trenches would involve excavation of perimeter drain trenches to collect and drain water contained within the tailings. This option was eliminated since it would have little effect hi dewatering the interior of the tailings. Additionally, the unstable tailings would create difficulties in excavating trenches which would not collapse during installation of the trench drain components. T5. Horizontal Drain System would consist of a network of perforated drains installed horizontally into the tailings near the base of the impoundment. These drains would operate by gravity and discharge to Tailings Pond No. 2 or an alternate holding area. The collected water would then be transported to the WTP as needed by tanker truck. 4.2 Description of Selected Treatment Technology The selected treatment technologies for this Work Plan, Options P3 and T5, will consist of a ponded surface water removal pipe and a system of seven (7) horizontal drains installed into the tailings near the base of the impoundment along the southern slope. The drainage pipes will collect water by providing a low-confining-pressure outlet. Water collecting in the pipes will be removed by gravity to existing Tailings Pond No. 2, immediately downstream of the main impoundment. Tailings Pond No. 2 will be used for the water collected from both the surface water ponding area and the horizontal drains. The collected water will then be transported to the Yak Tunnel Water Treatment Plant, as needed, by tanker truck. This technology is feasible using available construction equipment, procedures and practices. Care must be exercised in areas where construction activities occur adjacent to existing roadways, and utilities. This alternative could have a slight noise impact on the residents near

Colder Associates September 1995______4-3______943-2819 or adjacent to the tailing impoundment due to the drilling activities, construction of the collection and conveyance piping, and the occasional presence of a tanker truck. 4.2.1 Design of Ponded Water Removal System

A downslope pipe designed to remove ponded surface water from the top of the main Apache Tailings Impoundment will be a principal element of the dewatering system design. Drainage and removal of this surface water, which tends to be present at varying levels throughout the year, will aid in preventing infiltration as well as drying the tailings surface. A pipe will be constructed such that its inlet will capture ponded surface water and convey it via gravity down the western impoundment slope and into Tailings Pond No. 2, as shown on Figures 4-1 and 4-2. The pipe will be constructed of corrugated high density polyethylene (HDPE) for maximum flexibility and will be buried to a depth of at least 4 feet to prevent freezing. A valve will be installed in the pipeline on top of the main tailings impoundment to allow control of flow to Tailings Pond No. 2.

4.2.2 Design of Horizontal Drain System

A horizontal drain system will be constructed to remove groundwater from an area of the tailings impoundment that is scheduled for remedial excavation and re-grading during upcoming remedial activities. The system can be used to enhance long-term drainage of perched groundwater from within the remainder of the tailings impoundment. A phased approach will be used to evaluate system operational effectiveness and to develop criteria for subsequent system installation phases. The phased approach optimizes construction costs by providing full-scale testing of system performance and, if needed, allowing appropriate design modification. Modification may be appropriate because the range of engineering and hydrologic properties in the heterogeneous tailings mass may effect performance of a horizontal drain system designed on the basis of average or typical engineering and hydrologic values derived from existing data. Colder Associates September 1995______4-4______943-2819 This initial design phase included selection of a network of appropriate preliminary drain installation locations to effectively remove perched groundwater, particularly from proposed tailings excavation areas. Drain locations within the network were selected to maximize groundwater drainage prior to excavation and to provide data needed for evaluation of system operation.

The initial phase will involve installing a network of drain pairs on approximately 50- to 150- foot centers at the seven locations shown in Figure 4-1. Each drain pair will consist of two 150-foot long pipe components, one component will be installed near-horizontal and one inclined upward into the tailings impoundment at an angle of 5 to 10 degrees above horizontal. The near-horizontal drain component is intended to intercept groundwater moving down through the impoundment. The inclined drain component is intended to penetrate and drain perched groundwater units isolated within the impoundment. Figure 4-3 shows a typical drain-pair installation in the proposed excavation area along the southwest edge of the tailings impoundment. Each drain will consist of a 2 1/2-inch diameter, screened PVC pipe. Fine screen mesh will provide the openings in the drainage pipe. The system components are designed so that the groundwater entrance velocities will minimize silt and clay migration (infiltration) from the tailings into the drains. Periodic pipe flushing may be necessary to maintain the screen openings due to the fine nature of the tailings. Technological limitiations on the placement of filter pack material during horizontal drilling preclude the use of additional anti-clogging measures. The seven initial drain pairs will be connected to a manifold system and a drainage discharge pipeline. The horizontal drain discharge will be combined with the ponded surface water discharge in the discharge conveyance pipe, and all water removed from the tailings will be transmitted to Tailings Pond No. 2, located immediately downgradient from the impoundment (Figure 4-1). The manifold and associated discharge pipeline will be insulated and buried to a minimum depth of four feet to prevent freezing during cold weather. Colder Associates September 1995______4-5______943-2819 Initial flow rates from each drain pair are expected to be less than five gallons per minute. Flow rates may decrease as drainage progresses. Flow decreases are expected as hydraulic heads are lowered during dewatering of the tailings. Flow rates also may decrease as a result of drains being clogged by silt- and clay-sized tailings. System operations will be routinely monitored to evaluate performance, and pipe flushing will be performed as necessary. Design of subsequent phase drain-pairs and selection of locations will be based on evaluation of the initial phase network performance. Based on performance results, additional drain pairs may be deemed necessary for adequate removal of perched groundwater.

4.3 Installation and Start-up Activities

4.3.1 Ponded Water Removal System

At the approximate location shown on Figure 4-1, a downs lope pipe will be installed to drain ponded surface water from the main Apache Tailings Impoundment. The exact location will be determined in the field based on accessibility and the topography of impoundment surface in the ponded water area. The lowest point hi the vicinity of proposed pipe inlet location will be selected. The pipe will be covered over its entire length with at least 4 feet of soil to prevent freezing, except that the open pipe inlet will protrude from the soil to permit water entrance. No special screen, filter, or inlet structure is planned since flow rates should be low and the drained water should be fairly free of sediment. However, a screen or filter will be installed over the pipe inlet if excessive clogging by sediment is observed. Because of the irregular topography of the ponded water area, it is possible that one pipe inlet point may not be adequate to completely drain all areas of ponded water. If this becomes evident during initial operations, additional low points (sumps) will be excavated by hand into the tailings in the ponded water area as needed, and portable pumps and discharge hose will be used to convey ponded water to the primary pipe inlet area.

Golder Associates September 1995______4^>______943-2819 The pipe will be constructed of corrugated HDPE, which is non-corrodible and flexible enough to conform to the designed slopes. As mentioned above, a valve will be constructed in the pipeline at the top of the embankment slope. The valve will be placed in an insulated concrete valve vault. This valve should normally be open, but in the event of large amounts of precipitation or inaccessibility by the tanker truck, the valve may be closed to prevent excessive flow into Tailings Pond No. 2. The pipe outlet at Tailings Pond No. 2 will be protected by riprap or other reinforcement if flows from the downslope pipe are observed to cause excessive scour or mobilization of in-place tailings material.

4.3.2 Horizontal Drain System

Initial horizontal drain-pairs will be installed at the locations shown in Figure 4-1. Installation will require drilling borings to the total proposed drain length of 150 feet. Air-percussion, biodegradable-fluid rotary, or air-rotary drilling methods will be used to minimize clogging of tailings materials with drilling muds. Drams consisting of screened PVC pipe will be fitted with a closed end cap and inserted into the borehole to the total length of the borings. The two drain-pair components will be installed separately, within a few feet of each other.

After installation, tailings adjacent to the drain-pair components will be developed to increase inflow of groundwater. This will be accomplished by surging (if sufficient water is encountered) or by intermittent introduction of compressed air. For practical purposes, development will be minimal because the generally fine-grained tailings are not likely to form a suitable, natural sand pack adjacent to the drains. Each drain will be connected to the manifold and associated discharge pipeline. A drain access port will be installed at each drain-pair component to allow independent access to and testing of the components. The port will be large enough to allow access to the drams with appropriate maintenance equipment. The exposed drains, manifold and drainage pipeline will be insulated and buried to a minimum depth of four feet. The drain port access will be extended outside the buried area. Colder Associates September 1995______4-7______943-2819 4.4 Operation and Maintenance

4.4.1 Ponded Water Removal System

The ponded water removal system will be designed to function continuously without attendance. If additional sumps and portable pumps are needed to drain the ponded water, a daily visit by an operator will be necessary to ensure proper operation of this portion of the system. The pipe inlet will be checked periodically for signs of clogging or differential settlement. The valve will also be routinely checked to ensure that it operates properly. The general conditions of the main impoundment surface, the conveyance pipe outlet into Tailings Pond No. 2, and the storage conditions of Tailings Pond No. 2 will be checked at least monthly and after significant rain or snowmelt events. This will ensure that tanker trucks are scheduled appropriately, that the valve is closed if needed, and that Tailings Pond No. 2 does not overflow.

4.4.2 Horizontal Drain System The horizontal drain system will operate unattended and discharge into the manifold/discharge pipeline by gravity flow. Freezing weather should not interfere with system operation, although silt or clay may cause some clogging of the pipe drains. Drainage rates are expected to decrease with time but periodic maintenance of the drains may be required if drainage ceases or rates decrease unexpectedly. Methods used during drain-pair development will be used to re-activate groundwater flow into clogged drains, as required. Cleaning of clogged drains also may require periodic removal of silt or clay from inside the drains. This will be accomplished by use of pressured water jets or mechanical scraping to remove tailings material from inside the drains. Access to the drains will be through the drain access ports.

Golder Associates September 1995______4-8______943-2819 4.5 Data Collection and Management 4.5.1 Ponded Water Removal System

Performance of the ponded water removal system will be monitored immediately upon completion of the pipeline installation. Initial flow rates of removed water will be approximated and recorded at the Tailings Pond No. 2 outlet, and volumes of the combined ponded water and drain water will be tracked throughout system operation using tanker truck volume documentation. These water volumes will be documented on a monthly basis. The general conditions of the impoundment surface will also be documented montly. 4.5.2 Horizontal Drain System Monitoring of initial drainage system performance, including flow rates and visual turbidity, will begin within one week after installation. Depending on drainage system performance characteristics, weekly or monthly monitoring will continue hi order to obtain data on system operations, particularly data on changes in the system. The amount of water removed and treated (the combined volume of ponded water and drain water) will be tracked on a monthly basis using tanker truck records. The area at the southwest base of the main impoundment will be visually checked for toe seeps on a monthly basis. Periodic drainage performance data will be tabulated hi a data base and data curves will be drawn to demonstrate system performance. Water levels in existing monitoring wells previously completed in the tailings also will be measured monthly for the first three months and quarterly thereafter (or as needed depending on rates of change). Water level information will be included in the data base to assist hi evaluation of drainage system performance. Trends in the drainage system and monitoring well data will be analyzed to evaluate the need for additional drain pairs and to assist in design of subsequent system modifications.

Colder Associates September 1995______4-9______943-2819 4.5.3 Reporting

All data collected from the Treatability Study will be compiled internally by Asarco throughout the duration of the study and assembled into a final report at the end of the study. No other reporting of the data is proposed; however, data collected in the interim will be available for review if desired. 4.6 Schedule for Implementation Construction of first phase (3 drain pairs and ponded water September/October 1995 removal system) Start-up October, 1995 Phase II Construction (2 additional drain pairs) (if needed) May, 1996 Phase III Construction (Final 2 drain pairs) (if needed) July, 1996 Final evaluation of results September, 1996

Monitoring will be on-going throughout the duration of the treatability study. Phases II and III will only be constructed if needed based on preliminary results from Phase I drain-pairs.

Golder Associates September 1995______5-1______943-2819 5.0 RESIDUALS MANAGEMENT

5.1 Removal

As discussed in Section 4.0, water will be removed from the Apache Impoundment both via horizontal drains and surface water collection piping. Water collected from the horizontal drains will flow by gravity into a perimeter manifold system and discharge pipeline. This pipeline will be constructed of High Density Polyethylene (HDPE). Prior to exiting the main Apache Tailing Impoundment area, this flow will be combined with the drainage from the ponded surface water removal system. A single pipeline will then convey the combined drainage to Tailings Pond No. 2 for temporary holding until transport. The entire pipeline will be buried to a depth of approximately 4 feet to avoid freezing of the removed liquid. Waste tailings material derived from drilling activities will be placed on the Apache tailings impoundment. No storage or disposal of this material is proposed.

5.2 Storage

All water removed from the Apache Impoundment, both surface water and subsurface pore water, will be emptied from the HDPE pipeline into existing Tailings Pond No. 2. Only the existing low points of Tailings Pond No. 2, i.e., where water currently collects naturally, are proposed to be used for water storage. The storage capacity of this area of Tailings Pond No. 2 is estimated to be approximately 20,000 - 30,000 gallons. The levels in the pond will be kept to a minimum by removing collected water, as necessary. Valves will be incorporated into the piping system to control or shut off incoming flow if the pond fills at a rate which is greater than transport capabilities. Testing of pH, specific conductance, and other parameters will only be conducted if this information is needed by the tanker truck company or the Yak WTP operator. A loading pad will be constructed adjacent to Tailings Pond No. 2 to facilitate access for the tanker truck. A dedicated pump will be used to pump water from Tailings Pond No. 2 into the tanker truck. Golder Associates September 1995______5-2______943-2819 5.3 Disposal All water removed from the Apache Impoundment, both surface water and subsurface pore water, will be treated at the Yak Tunnel Water Treatment Plant (WTP), located approximately 1 mile from the Apache Impoundment. The removed water will be placed into the gravity in flow line (GIL), which will convey the flow to the WTP. Using this procedure, the water will undergo significant dilution and therefore the quality of this water will not adversely affect treatment plant operations.

Golder Associates September 1995______6-1______943-2819 6.0 HEALTH AND SAFETY Field activities for this study will be conducted according to the Site Health and Safety Plan, Yak Tunnel Operable Unit, California Gulch Site, Leadville, Colorado, Revision 2.0 (Res- Asarco, 1990).

Colder Associates September 1995______7-1______943-2819 7.0 OTHER ISSUES RELATED TO PROPOSED ACTIVITIES

7.1 Access Permission to access the Apache Tailings Impoundment and adjacent areas will be obtained prior to conducting field work for the Treatability Study.

7.2 Cultural Resources Consideration of Cultural Resources for all CERCLA activities at California Gulch is required by the National Historic Preservation Act since the Leadville area has been classified as a National Historic Landmark. The two primary documents that will be used to implement the requirements of the National Historic Preservation Act at the Site are: 1) the Programmatic Agreement between EPA, the State Historic Preservation Officer (SHPO), and the Advisory Council; and, 2) the Cultural and Historic Resources Identification and Evaluation (ID&E) Plan prepared by Asarco. EPA's Programmatic Agreement (PA) requires that remedial actions, if necessary, be conducted in accordance with certain stipulations in order for EPA to satisfy Section 106 of the Historic Preservation Act. The stipulations provide for: an identification and evaluation process for assessing effects on historic properties; development of a plan for management of historic properties; discovery of historic properties during remedial actions; involvement of interested persons (i.e., public); adherence to standards and guidance; and professional qualifications for this work. For the proposed dewatering activities, the "Guidelines for Conducting Minimal Disturbance Actions", an appendix to the Programmatic Agreement, will apply (Asarco, 1994b). Archaeological surveys will be conducted on the site prior to any major disturbance activities, such as will likely be associated with the final remedial action, to satisfy the requirements of the NHPA. Colder Associates September 1995______7-2______943-2819 7.3 Hazardous Materials Transportation Act The Hazardous Materials Transportation Act regulates the off-site transportation of hazardous materials and affects packaging, placarding, use of proper containers, and reporting discharges. Since the proposed dewatering treatability study involves transport of potentially hazardous liquid removed from the Apache Impoundment on public roads for transport to the Yak Tunnel Treatment Plant, these activities may need to comply with the Hazardous Materials Transportation Act. 7.4 Colorado Noise Abatement Act The Colorado Noise Abatement Act establishes maximum permissible noise levels for particular tune periods and land use zones. The proposed dewatering activities involve drilling and construction equipment, and therefore, the Noise Abatement Act must be considered. A summary of regulations is provided below. Construction projects are subject to the maximum permissible noise levels specified for industrial zones. These are: 80 db from 7:00 p.m. to next 7:00 a.m. During the hours between 7:00 a.m. and 7:00 p.m., the noise levels may be increased by ten db for a period not to exceed fifteen minutes hi any one-hour period. Sound levels of noise shall be measured at a distance of twenty-five feet or more from the property line. Since the Apache Tailings Impoundments are a few hundred feet from the nearest residence, it is not anticipated that excessive noise will be a concern during construction of the dewatering system. However, if excessive noise becomes a problem, steps considered to remedy the problem include: 1) operating during limited hours, 2) ensuring proper noise suppression equipment is used on equipment, and 3) installing noise screening or sound proofing.

Golder Associates September 1995______8-1______943-2819 8.0 REFERENCES Asarco. 1991. Hydrogeologic Work Plan, California Gulch Site, Leadville, Colorado. Prepared by Woodward-Clyde Consultants. Asarco. 1994. Tailings Disposal Area Remedial Investigation Report, California Gulch Site, Leadville, Colorado. Prepared by Woodward-Clyde Consultants. January. Asarco. 1994b. Draft Guidelines for Conducting Minimal Disturbance Actions. Prepared by Foothills Engineering. May. Bouwer, H. 1989. The Bouwer and Rice Slug Test - An Update. Groundwater Vol. 27, No. 3, pp. 304-309. Bouwer, H. and R.C. Rice. 1976. A Slug Test for Determining Hydraulic Conductivity of Unconfined Aquifers with Completely or Partially Penetrating Wells; Water Resources Research. Vol. 12, No. 3, pp. 423-428. Hvorslev, M.J. 1951. Time Log and Soil Permeability in Groundwater Observation. U.S. Army Corps of Engineers, Waterways Experimental Station Bulletin 36, Vicksburg, Mississippi. Res-Asarco. 1990. Site Health and Safety Plan, Yak Tunnel Operable Unit, California Gulch Site, Leadville, Colorado. Prepared by Woodward-Clyde Consultants. April. Turk, J.T. and J.O. Taylor. 1979. Appraisal of Groundwater in the Vicinity of the Leadville Drainage Tunnel, Lake county, Colorado. U.S. Geological Survey Open File Report 79- 1538. U.S. Environmental Protection Agency (EPA). 1987a. Phase I Remedial Investigative Report. California Gulch, Leadville, Colorado. 53-8129.0/W63781.R1. Prepared by CH2M Hill, Black & Veatch, ICF, PRC, and Ecology and Environment. May. EPA. 1988. Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA. OSWER Directive 9355.3-01. EPA. 1989. Phase II Remedial Investigation Technical Memorandum. Draft. California Gulch, Leadville, Colorado. Volumes I-VI. 53-8129.O/DEN63786.R1. Prepared by CH2M Hill, Black & Veatch, ICF, PRC, and Ecology and Environment. May.

Golder Associates TABLE 2-1 APACHE TAILINGS IMPOUNDMENT SURFACE WATER SAMPLING FIELD DATA SUMMARY Specific Dissolved Sample ID Discharge pH Temperature Conductivity Oxygen (gpm) (std units) (°C) (mmhos/cm) (mg/1) Ponded Water Sample L-APPDW-01-910917 N/A 1.71 17.1 20,200 4.0 Upstream Surface Water Samples L-APUPW-01-910918 330 6.68 9.5 1,001 7.7 L-APU1W-01-910918 1.8 7.92 14.1 314 6.3 Downstream Surface Water Sample L-CG03W-Q1-910817 11.7 7.50 17.2 1,205 5.1 Source: Water, Waste, and Land, Inc. Downstream surface water sample data added by WCC. TABLE 2-2 APACHE TAILINGS IMPOUNDMENT TEST HOLE DRILLING SUMMARY Test Hole Total Test Hole Completed as Inner Diameter Test Hole ID Completion Date Depth1 (ft) Monitor Well Boring Device2 (in) AP1B1 09/24/91 23.5 AP1TMW1 8 ',4 "HSA AP1B2 09/17/91 17.0 AP1TMW2 8'/4 "HSA AP1B3 09/17/91 24.3 AP1TMW3 8'/4 "HSA AP1B4 10/24/91 40.5 N/A 3V4 "HSA AP1B5 10/23/91 41.5 N/A 3V* " HSA AP1B6 10/22/91 42.0 N/A 3'/4 "HSA AP1B7 10/09/91 77.4 AP1TMW7 6" RCP AP1B8 10/23/91 63.3 AP1TMW8 8>/4 "HSA 11 AP1B9 10/21/91 34.0 AP1TMW9 8'/4 HSA AP1B10 10/22/91 27.0 AP1TMW10 8% "HSA AP1B11 10/24/91 22.5 N/A 3!4 "HSA AP2B1 10/29/91 12.0 AP2TMW1 8'/4 "HSA AP3B1 10/29/91 7.0 N/A 314 "HSA Measured from Ground Surface. 2HSA = Hollow Stem Auger. RCP = Reverse Circulation Percussion Dual Wall Casing. Prepared by Water, Waste, and Land, Inc. TABLE 2-3 APACHE TAILINGS IMPOUNDMENT MONITORING WELL COMPLETION SUMMARY

Monitoring Completion Tota1 l Screene1 d PVC 2Riser Well ID Date Depth (ft) Interval (ft) Height (ft) AP1TMW1 09/24/91 23.0 12.0- 22.0 3.0 AP1TMW2 09/17/91 14.4 9.0- 14.0 2.0 AP1TMW3 09/18/91 23.8 13.4- 23.4 1.6 AP1TMW7 10/09/91 75.2 62.2- 72.2 2.3 AP1TMW8 10/23/91 36.0 20.5- 35.5 2.0 AP1TMW9 10/21/91 19.8 9.3- 19.3 2.0 AP1TMW10 10/22/91 19.5 9.0- 19.0 2.5 AP2TMW1 10/29/91 7.2 4.6- 6.7 2.4

2'Total depth and screened interval measured from ground surface. Height of PVC casing above ground surface at time of well completion. Prepared by Water, Waste, and Land, Inc. TABLE 2-4 HYDRAULIC GRADIENTS AND GROUNDWATER FLOW DIRECTIONS CALIFORNIA GULCH SITE TAILINGS AREA Apache Oregon Gulch Oregon Gulch Colo. Zinc Lead Hamm's Mill Malta Alluvial Aquifer Alluvial Aquifer Perched Aquifer Alluvial Aquifer Alluvial Aquifer Alluvial Aquifer Measurement Hydraulic Flow Hydraulic Flow Hydraulic Flow Hydraulic Flow Hydraulic Flow Hydraulic Flow Period (1992) Grad. Direction Grad. Direction Grad. Direction** Grad. Direction Grad. Direction Grad. Direction January NA NA 0.052 S89W NA NA NA NA 0.031 N7W 0.008 S61W April 0.034* S36W* 0.053 S89W 0.130 N50W 0.017* S80W* 0.032 N12W 0.009 S65W June 0.035 S45W 0.051 S89W 0.160 N50W 0.018 S80W 0.032 N6W 0.009 S66W September 0.035 S40W 0.053 S89W 0.160 N50W 0.020 S84W 0.032 N6W 0.010 S68W

* = May 1992 estimate, insufficient data for April estimate ** = Assumed flow direction I I II 1 I I t

TABLE 2-5 ESTIMATES OF AQUIFER FLOW PARAMETERS CALIFORNIA GULCH SITE TAILINGS AREAS Apache Oregon Gulch Oregon Gulch Colo. Zinc Lead Hamm's Mill Malta Alluvial Aquifer Alluvial Aquifer Perched Aquifer Alluvial Aquifer Alluvial Aquifer Alluvial Aquifer Hydrogeologic Range Range Range Range Range Range Range Range Range Range Range Range Parameters______Minimum Maximum Minimum Maximum Minimum Maximum Minimum Maximum Minimum Maximum Minimum Maximum Inverse Effective Porosity (1/n) 2.86 10.00 2.86 10.00 2.86 10.00 2.86 10.00 2.86 10.00 2.86 10.00 Hydraulic Conductivity (ft/day) 5.20E-01 4.12E+02 2.12E-02 4.12E+02 1.26E+00 1.40E+00 5.81E-01 1.55E+01 4.91E-03 1.01E+00 1.20E+01 4.67E+01 Hydraulic Gradient (ft/ft) 0.034 0.035 0.051 0.053 0.130 0.160 0.017 0.020 0.031 0.032 0.008 0.010 Average Linear Velocity (ft/day) 5.05E-02 1.44E+02 3.09E-03 2.18E+02 4.68E-01 2.24E+QQ 2.82E-02 3.10E+QO 4.35E-04 3.23E-01 2.75E-01 4.67E+00 TABLE 2-6 APACHE TAILINGS IMPOUNDMENT GEOTECHNICAL TESTING SUMMARY Lab Geotechnical Tests Test Sample Sample Sampler Material Field Material Hole Sample Number No. Depth (ft) type' Type Description MC SV HY SG DD AL Other AP1B4 L-AP1B403T-01-911024 1 5.4-7.0 SS Tailings V. Silty Sand * * L-AP1B407S-01-911024 2 15.4-17.0 SS Tailings SI. Silty Sand * * * DS L-AP1B410S-01-911024 3 23.5-24.0 DC Tailings Clay & Silt * * * * * 4 L-AP1B413S-01-911024 4 31.5-32.0 SS Tailings Silty Sand * * * * AP1B5 L-AP1B502T-01-911023 5 2.0-3.0 DC Tailings Sandy Silt * * * L-AP1B507S-01-911023 6 18.0-19.0 DC Tailings Clayey Silt * * * AP1B6 L-AP1B602T-01-911022 7 1.6-2.6 DC Tailings Silty Sand * * * * L-AP1B608T-01-911022 8 18.0-19.0 DC Tailings V. Sandy Clayey Silt * * * AP1B8 L-AP1B802T-01-911023 9 3.5-4.0 DC Tailings Sandy Clayey Silt * * * * L-AP1B806S-01-911023 10 15.0-17.0 SS Tailings Silty Sand * * L-AP1B810S-01-911023 11 30.0-32.0 SS Tailings Sandy Clayey Silt * * * * * AP1B9 L-AP1B902T-01-911021 12 3.0-4.0 DC Tailings Sandy Clayey Silt * * + L-AP1B906T-01-911021 18 15.0-17.5 ST Tailings Clayey Sandy Silt + + * * * * TX,CON L-AP1B908T-01-911021 13 23.7-24.0 DC Tailings V. Clayey Silt * * * * * * AP1B10 L-AP1B1002T-01-911022 14 3.0-4.0 DC Tailings Silty Sand * * * L-AP1B1003S-01-911022 15 8.0-9.0 DC Tailings Silty Sand * * * L-AP1B1009S-01-911022 16 20.4-20.8 SS Tailings Clayey Silt * * * L-AP1B1010S-01-911022 17 23.0-24.0 DC Tailings Clayey Silt * * * * * AP1B11 L-AP1B1101T-01-911024 19 15.0-17.5 ST Tailings Clayey Silt * * * * * TX,P L-AP1B1102T-01-911024 20 20.0-22.5 ST Tailings V. Clayey Silt * * * * * * TX,P 1 Sampler types: SS-split spoon, DC-dry core, ST-Shelby tube. 2 Testing abbreviations: MC-moisture content, SV-sieve, HY-hydrometer, SG-specific gravity, DD-dry density, AL-Atterberg limits, TX-triaxial shear test, DS-direct shear test, P-permeability, CON-consolidation. Prepared by Water, Waste, and Land, Inc. TABLE 2-7 APACHE TAILINGS IMPOUNDMENT GEOTECHNICAL LABORATORY DATA SUMMARY

2 Lab Sample Laboratory 1 Moisture Drv Density Atterbers Limits Pe;rcent Minu3 s Specific 4 Test No. Material Description USCS Content (%) (PCF) LL PL PI 200 (%) Gravity Other Tests Hole AP1B4 1 V. SUty Sand SM 2.8 43 AP1B4 2 SI. SUty Sand SP-SM 7.0 11 3.08 DS AP1B4 3 Clay & Silt CL-ML 46.0 39 25 14 100 2.69 AP1B4 4 SUty Sand SM 6.6 19 2.67 AP1B5 5 Sandy SUt 15.9 66 2.53 AP1B5 6 Clayey Silt 44.8 100 2.48 AP1B6 7 SUty Sand SM 15.9 NON-PLASTIC 40 AP1B6 8 V. Sandy Clayey SUt 11.1 56 AP1B8 9 Sandy SUt 23.0 68 2.79 AP1B8 10 Silty Sand SM 8.9 30 AP1B8 11 Sandy Clay CL 30.1 33 22 11 75 2.93 AP1B9 12 Sandy SUt 19.0 75 AP1B9 13 Clay CL 35.8 44 24 20 100 2.83 AP1B10 14 SUty Sand SM 7.7 40 AP1B10 15 SUty Sand SM 2.1 18 AP1B10 16 Clay & Silt 25.6 100 2.77 AP1B10 17 Clay CL 29.5 32 23 9 99 AP1B9 18A SI. Sandy Silt ML 11.2 117.8 19 17 2 87 3.38 TX.CON AP1B9 18B TX.CON AP1U11 19A Clayey Sill 42.4 88.6 100 3.42 TX.CON, I' TABLE 2-7 (Concluded)

2 Lab Sample Laboratory 1 Moisture Drv Density Atterberg Limits Percent Minu3 s Specific 4 Test No. Material Description USCS Content (%) (PCF) LL PL PI 200 (%) Gravity Other Tests Hole AP1B4 1 V. Silly Sand SM 2.8 43 AP1B11 19B TX.CON AP1B11 19C TX.CON AP1B11 20A TX.CON AP1B11 20B Silt ML 48.2 75.3 45 31 14 100 2.70 TX.CON AP1B11 20C TX.CON AP1B11 20D P

1 Unified Soil Classification System (USCS) abbreviations: SM-silty sand, SP-poorly graded clean sand, CL-clay, ML-silt. Dual symbols indicate borderline classification. 2 Atterbcrg Limit abbreviations: LL-liquid limit, I'l.-plasiic limit, Pi-plasticity index. 3 Percent Minus 200: percent of soil passing the No. 200 sieve, or smaller Iliaii 0.075mm. 4 Testing abbreviations: DS-direct shear lest, TX-triaxial shear test, CON-consolidation test, P-permeability test. Prepared by Water, Waste, and Land, Inc. TABLE 2-8 APACHE TAILINGS IMPOUNDMENT GROUNDWATER SAMPLING RESULTS

Sample Number L-APITMW01- L-APITMW02- L-AP1TMW03- L-AP1TMW07- L-AP1TMW09- L-APITMW09- 01-911121 01-911121 01-911121 01-911122 01-911127 02-911127 Date Collected 11/21/91 11/21/91 11/21/91 11/22/91 11/27/91 11/27/91 MAJOR CONSTITUENTS AND INORGANICS Total calcium (mg/l) 415 132 79 61 401 398 Chloride (mg/l) 6 1 8 4 15 15 Fluoride (mg/l) .1 U 0.3 0.2 0.1 1.3 1.3 Total magnesium (mg/l) 245 59 32 26 1240 1230 Nitrate/nitrite (mg/i) .02 UJ .05 J 1.05J 1.23J .02 U .02 U Total potassium (mg/l) 8 3 3 2 58 57 Silica (mg/l) 34 13 16 18 25 25 Total sodium (mg/l) 3 9 6 4 9UJ 9UJ Sulfate (mg/l) 2960 605 J 235 J 138J 6090 5950 Total phosphonis (mg/l) .02 J .02 J .02 J .01 J .02 J .02J DISSOLVED METALS aluminum (ug/1) 1010 J 200 UJ 200 UJ 200 UJ 200 U 200 U antimony (ug/l) 120 U 120 U 120 U 120 U 5U 5U arsenic (ug/1) 20 U 20 U 20 U 20 U 5U SU barium (ug/1) 400U 400U 400 U 400 U 19.3 U 18.3U cadmium (ug/1) 79.6 10 U 10 U 10 U 1.3 U 1.2 U chromium (ug/1) 20 UJ 20 UJ 20 UJ 20 UJ SU 5U copper (ug/1) 56.1 SOU SOU SOU 5U 5U iron (ug/1) 149000 9250 100 U 100 U 32000 32200 lead (ug/1) 308 6U 6U 6U 5U SU manganese (ug/1) 256000 17600 6370 107 13900 14000 mercury (ug/1) .2U .2U .2U .2U .2U .2U nickel (ug/1) 333 SOU SOU SOU 21.2 U 26 U selenium (ug/1) 28.4 10 U 10 U 10 U 23.4 U 24.4 U silver (ug/1) 20 U 20 U 20 U 20 U .5U .SU zinc (ug/1) 132000 27000 619 20 U 548 550 OTHER WATER QUALITY PARAMETERS Alkalinity (mg/l) NR NR NR NR 56 J 66J Dissolved organic carbon (mg/l) SJ 4J 3J 3J 10 9 Total dissolved solids (mg/l) 4540 J 928 J 454 J 1140) 8010 8310 Total suspended solids (mg/l) 18 2U 2U 2U 4 6 field pH (units) 5.5 6.49 7.07 7.27 6.15 6.15 field specific conductivity (umhos/cm) 1,720 827 523 441 6,580 6,580 NR = not analyzed U ™ not detected J = estimated quantity TABLE 2-9 APACHE TAILINGS IMPOUNDMENT SURFACE WATER SAMPLING RESULTS Sample Number L-APPDW L-APU1W L-APUPW L-CG03W -01-910917 -01-910918 -01-910918 -01-910917 Date Collected 9/17/91 9/18/91 9/18/91 9/17/81 TOTAL METALS, MAJOR CONSTITUENTS, AND INORGANICS Aluminum (ug/I) 497,000 988 1080 116 Antimony (ug/1) 10. IB 60.0 U 60.0 U 1.1U Arsenic (ug/1) 53900 10.0 B 10.0 B 1.4BJ Barium (ug/1) 5500 U 200 B 200 B 31.7BJ Cadmium (ug/1) 2110 10.2 190 87.2 Calcium (mg/1) MR 34 117 146 Chloride (mg/1) MR 5U 5U 1 Chromium (ug/1) 5500 U 11.0 U ll.OU 11 U Copper (ug/1) 32000 50.0 B 280 13.6 Cyanide R R R R Fluoride (mg/1) NR 0.1 U 0.3 0.3 Iron (ug/1) 27,800,000 1070 1870 1970 Lead (ug/1) 560 J R R 41.8 Magnesium (mg/1) NR 15 56 72 Manganese (ug/1) 140000 82.4 15500 11300 Mercury (ug/1) 0.22 0.20U 0.2 U 0.2 U Nickel (ug/1) 11000U 40.0 U 40.0 B 36.2 BJ Nitrate/Nitrite (mg/1) NR 0.02 U 0.22 0.02 Potassium (mg/1) NR 5U 5B 3 Selenium (ug/1) R R 5.0 U R Silica (mg/1) NR 2 3 15 Silver (ug/1) 12.6 R R 0.55 U Sodium (mg/1) NR 5U 7 4 Sulfate (mg/1) NR 25 591 642 Phosphorus (mg/1) NR 0.01 U 0.01 U 0.01 Zinc 355000 728 41100 37300 DISSOLVED METALS Aluminum (ug/1) 495000 200 -U 200 U SOU Antimony (ug/I) 12.2 R R 8.1 BJ Arsenic (ug/1) 54100 10.0 U 10.0 U 1U Barium (ug/1) 2000 U 200 B 200 B 33.3 BJ Cadmium (ug/l) 2170 6.8 206 98.2 Chromium (ug/1) 2000 U 10.0 U 10.0 U 10 U Copper (ug/1) 25000 25.0 B 53.5 2.4 BJ Iron (ug/1) 27,800,000 100 U 100 U 223 Lead (ug/1) R 3.0 B 3.0 U R Manganese (ug/1) 144,000 15 16600 12800 Mercury (ug/1) 0.20 U 0.20 U 0.20 U 0.2 U Nickel (ug/I) 4000U 40.0 U 40.0 B 36.6 BJ Selenium (ug/1) 100 UJ R R 5U Silver (ug/1) 1.8 10.0 U 10. OU 0.5 U Zinc 361000 184 43000 40500 OTHER WATER QUALITY PARAMETERS Alkalinity (mg/1) NR 124 8 68 Dissolved Organic Carbon (mg/1) NR 2 2 2 Total Dissolved Solids (mg/1) NR 168 866 1010 Total Suspended Solids (mg/1) NR 12 14 142 Lab pH (units) NR 7.5 6 6.9 Lab Specific Conductivity (umhos/cm) NR 260 1010 994 B = indicates values above instrumnenl detection limit and below contract required detection limit U=not detected J=estimated quantity R=data rejected during validation NR = not reported TABLE 2-10 APACHE TAILINGS IMPOUNDMENT METHOD 1312 SAMPLES Sample Number L-AP1B101S- L-AP1B102S- L-AP1B202S- L-AP1B302S- L-AP1B4021- L-AP1B404T- L-AP1B406T- L-AP1B408S- L-AP1B502T- 01-910924 01-910924 01-910917 01-910917 01-911024 01-911024 01-911024 01-911024 01-911023 Impoundment Number 1 1 1 1 1 1 1 1 1 Test Hole Number •' AP1B1 AB1B1 AP1B2 AP1B3 AP1B4 AP1B4 AP1B4 AP1B4 AP1B5 Depth Interval 11-12' 16-17' 5-7' 4.8-6' 3.7-5' 9-10' 14-15' 19-20' 4-5' Date Collected 9/24/91 9/24/91 9/17/91 9/17/91 10/24/91 10/24/91 10/24/91 10/24/91 10/23/91 Sample Type FS FS HS I-S T T T T T Arsenic 10 U 10 U 10 U 10 U 10 UJ 10 U 10 10 U 10 U Cadmium 5U 5U 50.2 5UJ 1020 251 769 J 97.8 J 134 J Lead 3UJ 3.5 J 3UJ 28.2 128 J 2200 J 2390 J 5.7 J 33.2 J Zinc 26.5 J 99.7 J 1570 96. SJ 33800 11700J 75200 3660 1160

Sample Number L-AP1B507S- L-AP1B514S- L-AP1B516S- L-AP1B602T- L-AP1B607T- L-AP1B613S- L-APIB617S- L-AP1B802T- L-AP1B803T- 01-911023 01-911023 01-911023 01-911022 01-911022 01-911022 01-911022 01-911023 01-911023 Impoundment Number 1 1 1 1 1 1 1 1 1 Test Hole Number AP1B5 AP1B5 AP1B5 AP1B6 AP1B6 AP1B6 AP1B6 AP1B8 AP1B8 Depth Interval 19-20' 35.5-37' 40.3-42' 2.6-5' 10-17' 31-32' 41-42' 3.5-4' 5-7' Date Collected 10/23/91 10/23/91 10/23/91 10/22/91 10/22/91 10/22/91 10/22/91 10/23/91 10/23/91 Sample Type T T FS T T T FS T T Arsenic 10 U 10 U 10 U 12.8 J 10 UJ 10 UJ 10 UJ 10 UJ 10 U Cadmium 22.1 J 5U 226 J 7090 87.7 665 5 1790 5U Lead 25.9 J 3UJ 296 J 427 15.6 J 85.4 3U 1280 J 5J Zinc 486 191 J 5770 12100 4640 J 12300 38.5 51300 200 J

Sample Number L-AP1B804T- L-AP1B805S- L-AP1B807S- L-AP1B808S- L-AP1B809S- L-AP1B811S- L-AP1B812S- L-AP1B813S L-AP1B814S- 01-911023 01-911023 01-911023 01-911023 01-911023 01-91 1023 01-911023 -01-911023 01-911023 Impoundment Number 1 1 1 1 1 1 1 1 1 Test Hole Number AP1B8 AP1B8 AP1B8 APIB8 AP1B8 AP1B8 AP1B8 AP1B8 AP1B8 Depth Interval 9-10' 14-15' 19-20' 24-25' 29-30' 34-35' 39-40' 44-45' 46.7-47' Date Collected 10/23/91 10/23/91 10/23/91 10/23/91 10/23/91 10/23/91 10/23/91 10/23/91 10/23/91 Sample Type T T T T T T T T T Arsenic 10 UJ 10 UJ 10 UJ 10 UJ 10 U 10 UJ 10 UJ 10 U 10 UJ Cadmium 128 96.7 134 15.7 12.4 5U 5U 5U 11.6 Lead 1060 J 26.2 12.4 3.7 3.1 J 3.5 3U 5.2 J 20.8 Zinc 5190 1550 4990 217 401 J 20 U 22.6 189 J 144 TABLE 2-10 (Concluded) Sample Number L-APIB8I5S- L-AF1B815S- L-AP1B817S- L-AP1B9051- L-AP1B907S- L-AP1B910S- L-AP1B911S- L-AP1B1002T L-AP1B1005S 01-911023 01-911023 01-911023 01-911021 01-911021 01-911021 01-911021 -01-911022 •01-911022 Impoundment Number 1 1 1 1 1 1 1 1 1 Test Hole Number AP1B8 AP1B8 AP1B8 AP1B9 AP1B9 AP1B9 AP1B9 AP1B10 AP1B10 Depth Interval 49-50' 54-56' 59-61' 14-15' 18.5-19.5' 31-32' 32-34' 4-5' 12.4-14' Date Collected 10/23/91 10/23/91 10/23/91 10/21/91 10/21/91 10/21/91 10/21/91 10/22/91 10/22/91 Sample Type FS FS FS T T T FS T T Arsenic 10 UJ 10 UJ 10 UJ 10 UJ 10 UJ 10 UJ 10 UJ 10 UJ 10 UJ Cadmium 5U 5U 5U 17 6.2 19.5 13.7 242 31.1 Lead 42.8 3U 3U 50.5 3UJ 7.7 J 3UJ 71.7 13.9 J Zinc 113 101 32.6 569 90.1 465 J 91.1 15100 1370 J

Sample Number L-AP1B1008S L-AP1B1010S- L-AP2B102T- L-AP2B103T- L-AP3B102T- L-AP3B103S- -01-911022 01-911022 01-911029 01-911029 01-911029 01-911029 Impoundment Number 1 1 2 2 3 3 Test Hole Number AP1B10 AB1B10 AB2B1 AP2B1 AP3B1 AP3B1 Depth Interval 19-20' 24-25' 4-5' 8.8-9.8' 4-5' 5-7' Date Collected 10/22/91 10/22/91 10/29/91 10/29/91 10/29/91 10/29/91 Sample Type T T T T T FS Arsenic 10 UJ 10 UJ 10 UJ 10 UJ 50 UJ 10 UJ Cadmium 18.3 72.8 474 5U 448 5U Lead 3UJ 3UJ 212 J 30.6 J 1210 J 3UJ Zinc 3040 2830 28700 J 1640 J 72300 J 66.4 J All units in ug/L FS = Foundation soil sample T = Subsurface tailings sample U = not detected J - estimated quantity Color Map(s)

The following maps contain color that does not appear in the scanned images. To view the actual images please contact the Superfund Record Center at (303) 312-6473. DENVER WESTERAND RIN O GRANGE

LEADVILLE DRAINAGE TUNNEL _ Evons

Stray Horse Gulch Storr Ditch

CALIFORNIA GULCH

SMITH /"RANCH

TITLE SITE Denver, Colorado LOCATION MAP CUENT/PRO.ECT DRAWN DATE RB SCAL E JULY 1995 NO. 943-2819 APACHE DEWATERNG CHECKED MAY AS SHOWN DWG NO./REV. NO. TREATABUTY STUDY WORK PLAN REVIEWED JJ RLE NO. 2819A104 FIGURE NO. t-1 mmii ' ]

•-..''V \•. •.,.-- ---.•• ••\. ••-;•:•'.. '" - - ' • :!,--' •-'..•

LEGEND MONITORING WELL © TEST HOLE SURFACE WATER SAMPLE MINI-PIEZOMETER SURFACE WATER FLOW DIRECTION YAK TUNNEL WATER TREATMENT SURGE POND

SITE PLAN 0 150 300 600 CLIENT/PROJECT L. WOODWARD-CLYDE, TAILINGS DISPOSAL AREA Rl, 1994, FIG. 3-1 V i..--,-, ~^y\ :\* MAIN\ APACHEX i/ TAILINGS IMPOUNDMENT APACHE '"•-,, '^v. TAILINGS POND #2

EMBANKMENT FACE SAMPLE LOCATION CRUST AND TAILINGS BELOW CRUST - SAMPLE LOCATION

APACHE TAUNGS SURFACE TALJNGS LOCA7TO4S ASARCO JULY 1995 SOURCE : WOODWARD-CLYDE TAILINGS DISPOSAL AREA Rl, 1994, FIG. 3-2. TREATABLTTAPACHY E STUDDEWATERMY WORKQ PLAN X NOTE: • NW" WELL- LOCATrONS -ARE -APPROXIMATE-. EXPLANATIONS SCALE IN FEET AP - AMOC 1WMBS MEA n^_ A9MKMHOE UCN. CROUNDMER 00 - ORBBON OUUCH OG1TMWALUM»1 L MOHTOR WELL 910 IflEL COMTOJR BEMION M FEET m - jgpni£D m EM WHER LEVEL ELEW1UN ' ABOVCONTOUE HEW SEA RIBE LKTERWL - 20* 0 250 500 1000 M FEET A90VE HEM 9EA LEVEL -N- 10,100.5A5 , APPMDflMKTE TOPOGRAPHIC CONTOUR INTERVAL - 23' OMMMC - DOITED EUEUmOLEVEL NCONTOU M RFEET SOURCE : WOODWARD-CLYDE TAILINGS DISPOSAL AREA Rl, 1994, FIG. 3-3. 1 TLE OG1TMW5TAUR5 MPOUNWENT UONTtOR WELL ABOVE MEAN SEA LEVEL A WATER LEVEL EUVMIOM CONTOUR HTERVAL- 100 APACHE TALJNGS AREA WMHETMMIMTSOf S 10^21.26 " ALLUVIAL AQUFER GROUNDWATER Denver, Colorado ELEVATION CONTOUR MAP BEDROCKJM IMCPORMHDNH S PZ2 LOW. OKMMDMER FUW DATE OUTCROP OR CMT AUJMHL PODHCTEM DRECRON Awtmxwuc CLIENT/PROJECT DRAWN RB JULY 1995 JOB NO. 943-2819 UNDER THM SURFKAt WKTER LEVEL EtCVKDON M FEET ASARCO CHECKED SCALE DWG. NO./REV. NO. DEPOSITOOLUMUSU AND SOL 9661158 ABOVE UEMI «tt LEVEL S36° W APACHE DEWATERNG MAY 1" 500' 0.034 ft/ft TREATABLJTY STUDY WORK PLAN REVIEWED JJ RLE NO. 2819B098 FIGURE NO. 2-4 EPA REGION VIII SUPERFUND DOCUMENT MANAGEMENT SYSTEM

DOC ID # 3/$O 2>S PAGE# IMAGERY COVER SHEET UNSCANNABLE ITEMfSI Contact the Superfund Records Center to view this (these) document(s). (303-312-6473)

SITE NAA1F.

REPORT OR DOCUMENT TITLE

&/ &., DATE OF DOCUMENT ' ~~t DESCRIPTION OF IMAGERY Q/^f'^/ YES

DESIGN AND INSTALL 5SW ADDITIONAL REVIEW AND DEWATERING EVALUATE SYSTEM RESULTS PHASE o TREATABILITY OPERATE AND ;UJ TREATABILITY STUDY MAINTAIN SYSTEM STUDY INITIAL (APPROX. 1 YR); WORK PHASE REVIEW AND PLAN INSTALLATION EVALUATE NO RESULTS PREPARE TREATABILITY STUDY REPORT AND CONTINUE PREPARATIONS FOR FINAL REMEDIAL DESIGN

TITLE APACHE DEWATERMQ APACHE DEWATERMQ •mEATABUTY STUDY WORK PLAN Denver, Colorado TREATABUTY STUDY FLOW CHART DRAWN CHECKED REVIEWED DATE SCALE RB MAY JJ JULY 1995 NONE FILE NO. 2819A102 JOB NO. 943-2819 DWG NO./REV.NO. FIGURE 3-1 1Piio

DQWNS120PE PIPE RIED^ ^ ^""~~ DOW.N5LOPE PIPE

"""""•* ""v.

"' "" " "*V '"^ ~^ ^10100 10110 10120 -•-• 10130 -

APPROXIMATE LAYOUT FOR r— o

c CD c.- o B c APPROXIMATE UMIT OF MAIN IMPOUNDMENT h" ct

cC—_

CO co 0co1 o zm ~5mj— § s C.0O co g co O-£>J. CNO) CD

tIN) 10130.00

1012000 CE ROND 10110.00 INSULATING SOft-COVER •i ———— .m.^-^- ——— , ^^— —

: DRAINAGE COLLECTION & 10100.00S^ .MANIFOLD .CONNECTION,,rrr \TED HORIZONTAL-DRAIN PAIR SATURATED CONDTIONS ; ENCOUNTERED DURING : 7 ^ DRILLING, BORING DRY i 10090.00 NGS ^^^ ^™ "

200.00 NE

NOTE : SEE TAILINGS DISPOSAL AREA Rl REPORT, HORIZONTAL SCALE 1"=40' CALIFORNIA GULCH, FOR HYDRAULIC CONDUCTIVITY VERTICAL SCALE 1"-20' DATA AND TAILINGS CHARACTERIZATION.

CLICNT/^ECT TITLE APACHE DEWATERMG TYPICAL HORIZONTAL DRAM- TREATABBJTY STUDY WORK PLAN Denver, Colorado PAR NSTALLATKDN DRAWN CHECKED REVIEWED DATE RB MAY JJ JULY 1995SCALE AS SHOWN FILE NO. 2819B094 JOB NO. 943-2819 DWG NO./REV.NO. FIGURE 4-3 APPENDIX A 1 AND GEOTECHNICAL TESTING RESULTS TE ST HOLE AND M< DNITORING WELL S URVEY DATA • - — -— •^g"™^^^*'^^^™*^^***^^^^^ Test Hole/Monitoring State Plane State Plane Elevation 1 Ground 1 Well ID Northing Easting Top of PVC Elevation AP1B1/AP1TMW1 513,898.76 1 ,775,525.87 10,044.16 10,041.80 AP1B2/AP1TMW2 513,779.72 1,775,709.29 10,041.14 10,039.69 AP1B3/AP1TMW3 513,660.83 1,775,414.13 10,029.95 10,029.10 AP1B4 514,286.76 1,776,583.24 N/A 10,116.78 AP1B5 513,793.79 1,776,697.15 N/A 10,113.48 AP1B6 514,184.73 1,776,955.81 N/A 10,124.76 AP1B7/AP1TMW7 513,917.77 1,777,822.92 10.146.62 10.144.98 AP1B8/AP1TMW8 513,951.58 1,776,526.24 10.117.28 10,115.45 AP1 B9/AP1TMW9 513,968.80 1 ,776,843.87 10,114.17 10,112.83 AP1B10/AP1TMW10 513,704.89 1,776,994.57 10,114.65 10,113.80 AP1B112 514,090 1,776,596 N/A 10,111 AP2B1/AP2TMW1 513,968.93 1 ,776,062.88 10,059.95 10,058.16 AP3B1 513,950.59 1,775,902.77 N/A 10,047.55

2'All elevations are in feet above mean sea level. Final survey not completed, estimated Northing, Easting and Elevation. SUMMARY LOG EXPLANATION OF SYMBOLS AND ABBREVIATIONS USED ON TEST HOLE SUMMARY FIGURES

SPT BLOW COUNT - Blow counts are sum of counts from middle two 6-Inch Intervals. SAMPLE NUMBER - Pertinent digits from Work Plan sample numbering. SAMPLING METHOD: CL.£ C: •«o o«>

SAMPLE TYPE: C - Geochemlcal testing T - Geotechnical testing L - Lead speclatlon - Split sample N - Nutrient analysis sample A - Archived sample NR - No recovery SAMPLING LOG: slightly clayey clayey alluvium clay glacial outwash MOISTURE DESCRIPTION: D dry SM slightly moist M moist VM very moist W wet HOLE COMPLETION: DC cement/ bentonite 20/40 pip tenk pvc i locking cover /; groubentonltt e pellets sansilicda |slo tted pvc pv<: cap 1 4" dla

bentonite hole washed * *• "» cement » V V chips cave-in pea gravel 77V [*'•***»•. II "V**"" NOTES: 1. UNLESS NOTED OTHERWISE, HOLE COMPLETION DIAMETER IS 12 INCHES.

Date: WATER JAN SYMBOLS AND ABBREVIATIONS Project: 22909C SAMPLE NUMBER !—SAMPLING METHOD HOLE I—SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION O-i 0 10 20 30 40 50 D SM M W ALLUVIUM r-0 Mm* cobbl«» and bouldtr*. rounded

5- -5 NR brown, lubroundcd to angular .... ,..„...... - 10- - 10 - X 01-S ^-x LaJ. La.J O O

15- II - 15 Q2-S brown

20- -20 03-S

BOTTOM OF HOLE J 1 23.5' 25 "-25

Date: WATER JAN 1993 WASTE TEST HOLE AP1B1 AND Pro|ect: &—————me LAN. D MONITORING WELL AP1TMW1 22909C —SAMPLE NUMBER —SAMPLING METHOD HOLE —SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 10 20 30 40 50 D SM M W r-0 O-i ALLUVIUM oi-s oronglih brown, rounded

5- -5 02-S gray

- 10- MO - 03-S oranjlih brown O_ a. Ul aUJ

15- 1-15 04-S fractured rock 2fi2l BOTTOM OF HOLE 17.0' 20-i L 20

Date: WATER JAN 1993 TEST HOLE AP1B2 AND Project: LANDwe. MONITORING WELL AP1TMW2 22909C I—SAMPL-SAU E NUMBER I—SAMPLIN_ G METHOD HOLE I—SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0- ) 10 20 30 40 SO [3 SU M V. ALLUVIUM r-0 01- S N A i lighbrownt ,orangls roundeh d W '

S

5- ————— H- 02- S C brokelight nbrow rocnk to tan -5

_ 10- so - 10 UJ 03 C light brown to tan UJ uU.l > ~ s UI z >*$ Q_ Ul LaJ. ° 15- •- r- 15 o 04- s C 'X-

• I • • . _ • H «jn •— 05- s C 20 I broken rock kS*

light brown to tan > 06- broken rock s ±3C >§2S: BOTTOM OF HOLE L 75- 24,3' 25

Date: WATER JAN 1993 WASTE TEST HOLE AP1B3 AND Project: &—————me LAN. D MONITORING WELL AP1TMW3 22909C SAMPLE NlJMBER t— SAUPLI1KC METHOD HOLE — SAM>LI£ TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) S( }ILS LOG COMMENTS DESCRIPTION 0 10 20 30 40 50 0- t> SM M W TAILINGS / - u 01-TfF ,-•'..-'; i / tan, fine to / medium / / ' '•' "•••":' < r-- ••••- - / / 02-T / / gray / / 5- t black to gray / -5 ...... < ...... Interbedded / K 03-Tj %]' ~ / / / • / / 04-T black to gray, / ^ medium, pyrfle / / _ 10- / / -10_ Ul Ul 05-T| NONE ...... >. Ul u. * / u. z '•"-»"'• I'i- z • ( > r 06-T 1I— Qt-. ... r Q. Ul C Ul S T TAILINGS tan r „ 'iffif < V * r « ) r 08-S '** "'.": r 20- 09-S NONE ,•"'•*! '"-7 < >•••••• ••-•••... -

( \ 10-S brown, medium I 25- 1-"• *'*. '. 25 A 11-S NONE • .'".';...' ,*j tan ( / / • / | ••••...*.*;•. *-.. /• -i ( 1 / / / 12-S brownish orange, ... / lev to high plattlclty / 30- / / -30 13-S ... / * 1 / / • / 6* —— / tan, medium ... / u-s / / C / 35- • •"!";• I*'--; / / -35 ^ - ...... J1 L. . • 15-S NONE ^ / / - • / . // •*— C ... r — * 16-S * / / S5> / s 17-S NONE BOTTOM OF HOLE / -40 ' 40.5' T Dry 1Q/24/9 •* V Date: WATER JAN 1993 *^ WASTE TEST HOLE AP1B4 Pro|ecf: \| r & LAND 22909C SAMPLE NUMBER SPT BLOW COUNT 1 — SAMPLING METHOD MOISTURE (BLOWS/FOOT) r SAMPLE TYPE DESCRIPTION HOLE 0- 3 10 20 30 40 50 SOILS LOG COMMENTS I) SU U W COMPLETION ,'j : -. •: TAILINGS -0 01 -T N i ton. fln« T •>-* 02-T "":.•* -. •-•*" i "• ? gray to black / C 'v;-rl 5- i -5 03-T >-£} gray to black, •'•}t lnUrb«dd*d |j 0 ^ C %.--^ arang* to lan _ 10- 1 $$ gray to black, fin* -10_ Ld to medium LJ 04-T Ul U. ••• --- •-- -•••• ••••- tan -H >-••• --• Ul. 1C z lan to y«llow and 0 z gray, tnt«rb«dd*d. X 05-T fin* ... 0. 1Ul . C ^ Ul ° 15- "=PS, TAILINGS 15° •••• -•-• •-- "-• •-- 06-S ^i ._H >...-...-. ... C * '-1k *• tan to orang* and # iSX^ gray, lnt«rb*dd«d, At.,y, ^ ^* ^ m.dlum to high •-^ ^ ^ 3-c i plaittclty fy 07-S T t \K*f\l ! •^ orang* to rtddtih C gray 20- / -20 9 08-S C §••'•£*•S tan, fin* H > ^ tan to oranglsh if-ii-e^ y*llow ^-* 09-S •-v-i C 4-fJ ^ -25 ^P 10-S -H >••-• - f C ;p H • ... 11-S *1( ^ brownish orang* 30- C s lan P -30 ...... 0...... 12-S C ¥ -H >...-. - ... ^,xV ^f *> ft* 13-S ^•_•.!•.•- C hf<^ 35- ft \ % -35 ^ 14-S C ...... s- -^ -~— ^ •-* 15-S ^i *L — » C fi ALLUVIUpink anMd tan with 40- s^\; broken and d«- -40 ...... < > 16-S compoicd rack -H >-- -•- m — C BOHOM OF 1 HOLE r •— !i 41. S Dry 10/23/9 I1 2 Date: WATER JAN 1993 CDIA ^r WASTE TEST HOLE AP1B5 Project: a. ^r & LAND 22909C SAMPLE NlJMBER SPT BLOW COUNT I — SAMPLIKIG METHOD MOISTURE (BLOWS/FOOT) SAMI 'LE TYPE DESCRIPTION HOLE 0- 3 10 20 30 40 SO St )ILS LOC COMMENTS 0 SM M W COMPLETION TAILINGS -0 01 -T r OT red. Interbedded, fine •>-•» 02-T black to gray, / 5- fine // -5 03-T C r!'11}'^! -H >•"•• " [ •-• 04-T / C 10- - 10 05-T * * +-0 06-T 1C | 15- $ - 15 07-T \ * C 08-T T Ul C Ul 7n u ' "' * V • orange layer, fine Ul u. ^ ''*••* TAILINGS zu £ 09-S Z ...H>...... tan, fine • H r-H r / z X Xt— Ua.l / a. Q 10-S S-:••$•i£ aUl 25- '^:! f : -25 ...... )...... n-s v^( ••"< r-H r-- red layer, coarie • 12-S ft light reddlih orangi ... 30- tan layer, coon* -30 13-S, 1 light reddish -H >•-•• •- orange, coarie 0 s- — - 14-S reddish brown, ; eoarte 35- \ -35 13-S | "* 1 0 1S-S !iC ALLUVIUM 40- - » 1 gravel and de- -40 & composed rock 17-S ... m — C BOTTOM OF1 HOLE 1 f — • ooo o OOO O

"* 5OOO < 42.0 DRY 10/22/S \ 2 WATER Date: |^^ WASTE TEST HOLE AP1B6 JAN 1993 CtoO ^ Pro|eet: ol r & LAND 22909C I—SAMPLE NUMBER I—SAMPLING METHOD HOLE I—SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0 tQ 20 30 40 SO 0 SM M W TAILINGS r-0 Ol-T orangoror e to gray, f fin* to medium orange to red / 02-T gray to black / 5- pyrlt. -5 03-Tl / 0*-T / C,L 10- TAILINGS - 10 mediubrownm, fin* to brown to gray a. 05-Sl a. UaJ UaJ 15- pyrfte h 15 OS-S layebrowrn with orang* 07-S 20- -20 brown

08-S .~<'.".f' 25- r ih r -25 »*;y-\ :'"* *"" ":> >'-•*"•

09-S mediubrownm, lnt*rfa*dd*d, 30- -30 10-Sl brownlth red brown tl-S 35 -i U35 FIGURE 1 OF 2 Date: WATER JAN 1993 TEST HOLE AP1B8 AND Projoct: LANDnee. MONITORING WELL AP1TMW8 22909C I—SAMPLE NUMBER SAMPLING METHOD HOLE I—SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0 10 20 30 40 50 D SM M W 35-, r35 mediubrownm, fin* to TAILINGS brown, !nt«rb«dd«d 12-S 40- -40

13-S 45- -45 U-S brown ALLUVIUM X fractured and de- Q. composed rock a. Ul 15-S sl LJ Q 50- blackand , orangwhit*e , gray, ^50 Q

red, yellow, purple, 55- 16-S composefracturedd anrocd k de- -55 IIP 60- 17-S brown, black, white -60

BOTTOM OF1 HOLE S3.3 65-1 L65

FIGURE 2 OF 2 Date: WATER JAN 1993 WASTE TEST HOLE AP1B8 AND sm MONITORING WELL AP1TMW8 Project: (L &—————we LAN. D 22909C •SAMPLE NUMBER I—SAUPLINO METHOD HOLE I—SAMPLE TYPE COMPLETION1 SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0 10 20 30 40 SO D SU U W TAILINGS r-0 Ot-T tan to gray. fln« ra 02-T T 5- C -5 gray, Int«rb«dd«d 03-T low pladlelty

10- - 10 Ld 04-T UJ

05-T gray. 1nt«rb«dd«d, Q. UaJ. m«dlum plasticity LJ Q 15- - 15o 06-T ti gray, fin* II TAILINGS 07-S tam«dlun tom brownto hig, h 20- plartlctty -20

08-S tan to r«dd!«h brownhigh ,plasticit mvdluy m to '.•••: 25- -25

09-S taeoarsn t*o brown,

30- tan to reddish -30 10-S plasflcltbrown,y mtdlum ALLUVIUM 11-S yellow to tan sanfractured d rock and BOTTOM OF HOLE 35 J 34.0' L35

Date: WATER JAN 1993 TEST HOLE AP1B9 AND Pro(ect: &—————we LAN. D MONITORING WELL AP1TMW9 22909C i—SAMPLE NUMBER I—SAMPLING METHOD HOLE — SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0 10 20 30 *0 50 0 SM M W O-i r-0 01-sQIBT TAILINGS mediudork mbrown, fin* tc 02-T gray brown 5- -5 t-;f t ip-'Ff 03-S tan

TAILINGS 10- tan. lnt«rb»dd«d - 10 Q4.-S

05-S ^f— UJ 06-S u. E 15- 15 ~* 07-S fp X CL UJ „., TAILINGS' -20 20- brown to orang*. 09-S rntdfum

10-S !v h brown to orange 25- wTif-!>,

30 -1 1 Date: WATER JAN 1993 WASTE TEST HOLE AP1B10 AND Projsct: &—————me LAN. D MONITORING WELL AP1TMW10 22909C •SAMPLE NUMBER —SAMPLING METHOD HOLE I—SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0- 0 tO ZO 30 40 50 0 SM M W TAILINGS, fin* to r 0 m«dlum

5- -5

UJI - 10- x -10 ^ a. a. uai aUJ

15- - 15 01-T Flngra»y to block.

20- TAILINGS -20 02-T tanhig,h medium to

BOTTOM OF1 HOLE 22.5 Dry 10/24/91 2 25- -25

30-1

Date: WATER JAN 1993 WASTE TEST HOLE AP1B11 Profect: &—————we LAN. D 22909C I—SAMPLE NUMBER —SAMPLING METHOD HOLE I—SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (SLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION 0 10 20 30 40 50 D SM M W O-i 1-0 TAILINGS 01-T tan, yellow, and brown, low to medium 02-T oranglih black, c „ fin* -5

03-T I a. aray a. QUJ 1 ALLUVIUM UJ 10- orange, rounded - 10a 04-S BOTTOM OF HOLE 12.0'

15-i L 15

Date: WATER JAN 1993 TEST HOLE AP2B1 AND Pro|«ct: MONITORING WELL AP2TMW1 22909C I—SAMPLE NUMBER I—SAMPLING METHOD HOLE —SAMPLE TYPE COMPLETION SPT BLOW COUNT MOISTURE (BLOWS/FOOT) SOILS LOG COMMENTS DESCRIPTION O-i 0 10 20 30 40 SO D SU U W TA1UNCS r-0 01-T fin*brow, n lowto torangeo high, oranglsh brown, 02-T fin* 5- ALLUVIUM -5 orang*. brown, and 03-S tan, roundtd BOTTOM OF MOLE 11! 7.0' Dry 10/29/91 iI- ua.i ua_i a 10- - 10a

15-1 L- 15

Date: WATER JAN 1993 TEST HOLE AP3B1 AND Pro|«cf: LANDwe. MONITORING WELL AP3TMW1 22909C 1 i 3:31= 0- - —— — ——— 1——— — 0.5- fine SAND with SILT, CLAY .• ^—GRAVEL APRON 1 * —————————————————————— S.O — — ——————— 8" SCHEDULE 40 STEEL clayey SAND, small amount _ , PROTECTIVE CASING fine GRAVEL * '* 71S 10- —————————————————————— 1 0.0' — A sandy CLAY with GRAVEL, A and COBBLES

^ n —————————————————————— 20.01 — • ' - ——————— CEMENT-BENTONITE GROUT _- gravelly CLAY with SAND. ;!: A" C\ 1 (CU TUDCAH O\/f* and COBBLES CASING SCHEDULE 40 30-

—————————————————————— 3S.01 — U^—l UJ Li. 5 40- i • x ; gravelly, sandy CLAY D_ QUl

50- —————————————— COBBLES —— 50.01 — silty CLAY, small amount 1 of GRAVEL ^/ —— S2.5 —————————————————— 55.0- — V f//y >— ——————— BENTONITE • 2^ —— 56.0' sandy, gravelly CLAY, -• ——————— 20-40 COLORADO SILICA SAND 60- BOULDERS . ."- —— 62.2' ———————————————— ss.o1 — • " • ———————— 4" FLUSH THREAD 10-SLOT PVC . SCREEN SCHEDULE 40 70-• , • sandy GRAVEL with SILT "___- —— 4" PVC CASING AND ~ . ---"""'^ BOTTOM CAP SCHEDULE 40 • *•»— —— 75.2' —————————————————— 77 4. — —— 77.4' 80- 1— — 9"

WATER Date: NOV 1992 WASTE MONITORING WELL AP1TMW7 Project: &——————me LAN. D COMPLETION DETAIL 103.1 TJVBORATORY TEST DATA SUMMARY WWL TCL MOISTURE DRY ATTERBERC PERCENT SPECIFIC SAMPLE SAMPLE CONTENT DENSITY LIMITS MINUS 200 GRAVITY NO. NO. (I) (PCF) LL PI, PI (Z) L-AP1B403T-01-911024 1 2.8 — _ _ _ 43 _ L-AP1B407S-01-911024 2 7.0 11 3.08 DRILL L-AP1B410S-01-911024 3 46.0 CUTTINGS 39 25 14 100 2.69 L-AP1B413S-01-911024 4 6.6 • - - - - 19 2.67 L-AP1B502T-01-911023 5 15.9 - - - - 66 2.53 L-AP1B507S-01-91 1023 6 44.8 - _ _ _ 100 2.48 L-AP1B602T-01-91 1D23 7 15.9 - NON-PLASTIC 40 - L-AP1B608T-01-911022 8 11.1 - _ _ - 56 - L-AP1B802T-01-911023 9 23.0 - _ _ _ 68 2.79 L-AP1B806S-01-911023 10 8.9 - _ _ _ 30 - L-AP1B810S-01-911023 11 30.1 - 33 22 11 75 2.93 L-AP1B902T-01-911021 12 19.0 - - - - 75 - L-AP1B908T-0 1-9 11021 13 35.8 - 44 24 20 100 2.83 L-AP1B1002T-01-911022 14 7.7 - - - 40 - L-AP1B1003S-0 1-9 11022 15 2.1 - _ 18 - . L-AP1B1009S-01-911022 16 25.6 - _ _ _ 100 2.77 L-AP1B1010S-01-911022 17 29.5 - 32 23 9 99 L-AP1B906T-01-911021 L-AP1B906T-01-911021 IS18CA 11.36.62 117.8 19 17 2 87 3.38 L-AP1B1101T-01-911024 19A 42.4 88.87.65 30 23 7 10908 3.42.721 L-AP1B1102T-02-911024 20B 48.2 75.3 45 31 14 100 2.70 5000

1000 2000 3000 4000 5000 6000 7000 8000 9000 10,000 p and p' (psf) a - p o — p'

WATER FIGURE Dote: MAY 1992 WASTE APACHE TAILINGS SAMPLE #18 p - q DIAGRAM Project: &——————— LAN— INCD. 103 5000

4000

3000 a.in

1000 2000 3000 4000 5000 6000 7000 8000 9000 10.000 p and />' (psf) o — p a — p'

WATER FIGURE Date: MAY 1992 WASTE APACHE TAILINGS SAMPLE #19 p - q DIAGRAM Project: &—————————INC LAN. D 103 5000

4000

3000

OM.

1000 2000 3000 4000 5000 6000 7000 8000 9000 10.000 p and fi' (psf) o - p a - p'

WATER FIGURE Date: MAY 1992 WASTE APACHE TAILINGS SAMPLE #20 p - q DIAGRAM Project: &————————INC LAN. D 103 Prnjprt: 4^Aft.CO Tw'.l'.rta*. __ WATETTZT^JL JLR« £V rnlculofprf By- ^^ts*>^^ vx/ A C T r Project No- 1O3> Checked By: Tnsk- - .&.LAN . ... ——— D..rue. nn**-

P' - - ISA •2SS5- 106*? S B 878 2246 3^23 /I OH R's cifia.e

2629 «EDV«NC R0*0 SUITC :00 PORT COUJNS. COLORADO MS2fi (303) 22S-JS3S FAX (3O3) 22S-»475 WATFTT/TL.JR I dcPmjWtv 1 - ASA^co T»;V;«.>^i Pnlrnln*.^ R • ^ttrX" W A S T F Project Nn .• , \O~5> Checked By: & T AND Tnsk! - Dot«-

AT D€(/MTOfi.

P

2771

4000 -

r ^T

2629 REDWING ROAO SUfTE 200 PORT COUJNS. COLOfWDO 80526 (303) 226-3535 FAX (303) 226-6*7S PrnjW+- ^S4CCO -p»;l;^5 rnlonlntpH Py mwv WATFTT^VJ—————————L U/1.RV — ^k^KLLA^^Sor r HWAST7 A f> *¥* E 1"" PrnjpM No- 103 Checked By: & 1 AND Tc^k' Ap^^1 h ^ On*!.-

/I OH ft' T>e«Jc

HA 2380 738 V6

3000-

—--V N. 1000 -

jcoo -vf- tooo

2629 REOWNC ROAD SUITE 200 FORT COUJNS. COLORADO 80526 (303) 226-3535 TAX (303) 226-6475 WATER Project: dS AUCO T4tUA/6i Calculated By: \far' WASTE Project No.: _.,_ 103 rh^rkeH By: >«*cA« &LANDtnr-_ Task: A% Date:

Sf /

People. Dev««.1er TD \°IA 2557 IIO? 2302

= 20.85*

2629 REDWING ROAD SUITE 200 TORT COUJNS, COLORADO 80526 (303) 22S-3S3S FAX (303) 226-W73 ^VY 7A ^HT^ V* ProierA- ASA&& lA'.l.'^S rnlr.ilnfpH By * O r WATER ^Sfef-^ «7 A c T C Proj^i Nn • \O2> Checked By: nnf*.- & I AN!«,

Pec.lt.

5. "Zo 15/8 253 •27 f 2 IS3S 7/cT?

3000-

1OOO - . x\, looo isoco— i i ——— i

= ?-

\

2679 REDWING ROAD SUITE 200 FORT COLLJNS. COLORADO M526 (303) 226-3515 FAX (303) 226-M75 WATER By: WASTE Project No. Checked By: &LAND Task:

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O loco

oi. =

2629 REDWING ROAO SUITE 200 PORT COUJNS. COLORADO M526 {303) 22G-3S3S FAX (303) 226-6475 - 30

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;::r:i: 11 w i :.i: /o £0 3° NORMAL PRESSURE IN LBS. / SQ. •=:RMEASILITY TEST - BACK PRESSURE CONSTANT HEAD

-CLIENT CE&I JOB NO. 2107-01 BORING NO. L-AP1311-01-T-01 SAMPLED 10-24-91 DM — DEPTH 15 - 17.5' TEST STARTED 12-16-91 DCW SAMPLE NO. 4JV /?/* TEST FINISHED 12-26-91 SOIL DESCR. (frrs^si Gulch SETUP NO. 3N _TEST TYPE TX/Pbo SATURATED TEST Yes CONF. PRES. PSF 1440 AT FIELD MOIST. No ""MOISTURE/DENSITY BEFORE AFTER DATA TEST TEST — Wt . Soil •*- Moisture 897.1 854.2 Wt . Wet Soil & Pan (g) 906.0 863.0 Wt . Dry Soil & Pan (g) 638.8 638.6 __Wt . Lost Moisture (g) 267.2 224.3 Wt . of Pan Only (g) 8 .9 8.9 Wt. of Dry Soil (g) 629.9 629.9 Moisture Content % (g) 42.4 35.6 -Wet Density PCF 126.1 131.2 ~ry Density PCF 58.6 96.8 Init. Diameter (in) 2.398 (cm) 6.091 Init. Area (sq in) 4.516 (sq cm) 29.140 _^Init. Height (in) 6.000 (cm) 15.240 ""Vol. Bef . Consol . (cu ft) 0.0156S Vol . -After Consol . (cu ft) 0.01435 Effective Porosity % 55.17 —Constant Head (?SI) 2.00 (cm) 140.79 Time Time Init. Final Head Permeability __ Burette Burette Corr . k Min Sec CC CC CC cm/sec 994.0 59640 48.5 35.9 17.9 9.45-07 "~ 605.0 36300 35.9 30.2 30.7 7.8E-07 765.0 45900 49.4 41 .6 13.3 7.3E-07 685.0 41100 41 .6 35.2 23.2 7.2E-07 — 791.0 47460 35.2 28.5 32.3 7.IE-07 1325.0 79500 49.5 37.0 16.4 6.9E-07 1473.0 88380 49.5 35.7 17.3 6.9E-07 _ 1415.0 84900 49.5 36.0 17.1 7.0E-07

ADVANCED TERRA TESTING, INC. "'ERMEABILITY TEST - BACK PRESSURE CONSTANT HEAD

- CLIENCE&I T JOB NO. 2107-01 BORING NO. L-APlBil-02-T-Oi SAMPLED 10-24-91 DM DEPTH 20 - 22.5' TEST STARTED 12-30-91 DCW SAMPLE NO. 2D TEST FINISHED 01-12-92 SOIL DESCR. Oregon Culoh SETUP NO. 9S TEST TYPE TX/Pbo SATURATED TEST Yes CONF. PRES. PSF 720 AT FIELD MOIST. No

MOISTURE /DENSITY BEFORE AFTER DATA TEST TEST Wt . Soil T Moisture 486.7 469.9 Wt . Wet Soil & Pan (g) 495.5 478.8 Wt . Dry Soil & Pan (g) 334.5 334 .5 Wt . Lost Moisture (g) 161 .0 144.3 Wt . of Pan Only (g) 8 .9 8.9 Wt . of Dry Soil (g) 325.6 325.6 Moisture Content % (g) 49 . 4 44.3 Wet Density PCF 112.5 115.3 Dry Density PCF 75.3 79.9 Init. Diameter (in) 2.393 (cm) 6.091 Init. Area (so in) 4.516 (sa cm) 29.140 Init. Height ( in } 3.650 "(cm) 9.271 Vol . Bef . Consoi . (cu ft) 0.00954 Vol. After Consol.. (cu ft) 0.00398 Effective Porosity % 56.72 Constant Head (?SI) 1.00 (cm) 70.39 Time Time Init. Final Head Permeability Burette Burette Corr. k Min Sec CC CC CC era/sec 326.0 49560 49.7 29.2 • 14.4 2.3E-06 787.0 47220 49 .6 40.?. 9.3 l.OE-06 669.0 41340 40.2 33.3 16.9 9.9E-07 605.0 36300 49 .8 42 .6 8.0 9.6E-07 343.0 50580 42.3 34.7 15.0 9. IE-07 524.0 31440 49.7 43.9 7.6 9.3E-07 984.0 59040 43.9 34.6 14.6 8.9E-07 478.0 28680 50.0 44.6 7.1 9.42-07 856.0 51360 44". 6 36.5 13.4 3.7E-07 702.0 42120 50.0 42.5 8.1 9.0E-07 725.0 43500 42.5 36.1 14.5 8.3E-07 547.0 32620 49.9 43.9 7.5 9.2E-07 346.0 50760 43.9 36.3 13.8 8 .4E-07 1480.0 88800 49.6 35.8 11.4 8.3E-07 1439.0 86340 49.9 36.6 10.9 8.22-07 1366.0 81960 49.7 37.2 10.7 8.1E-0? ADVANCED TEFxRA TESTING, INC. lilt i i i i i ( i t t I I I I CONSOLIDATION DATA )-) , /. 20/5 L-AP1B9-06-T-01 #3A, @ 1440 psf Conf. 0 O.foO

-2 o co '•4O^ -4 Qa> a> _c o -6 -<5h -7 60 -8 240 4 8 10 12 14 16 18 360 Square Root of Time In Minutes D Time in Minutes CONSOLIDATION DATA <%= /.m L-AP1B9-06-T-01 #^B. ® 2880 psf Conf. H * "^ I! 0. 10

-4 - — V o0 \ c 8 c I • 0 m1U t> 51 Qq> \\ q> — 1* 4* E \V o —16 - 10a -11 -20 - \V 1.71 — » >^^ >—. -22 - -e= • — •— ~. i-~>. ^ 31 — B- — i MM^_ " •"••! I 1 30 —— { i i ~e~ ••••.•!!• ••'••Ill M 1 . —— -{ **> 4 V, 60 —24 — i ——— 1;t JU 0 0 2lZ 4 6 8 10 12 14 16 18 J -I V f ^-((O Square Root of Time in Minutes -4^-- D Time in Minutes cv- o^C^— — — • \i>,o" tv~ oJi^l ±£ 1 V I i [ I I I I 1 I CONSOLIDATION DATA H- •.«*. L-AP1B9-06-T-01 5760 psf Conf. 0

oO oc -k-o> Da> Eo

-30 360 18 Square Root of Time in Minutes D Time in Minutes

0 0

OZ 5u Lu uQ y 5D O

SQUARE ROOT OF TIME l\l MINUTES D Time in Minutes •v • * f.?OiS"

CONSOLIDATION DAT:A L-AP1B11-01-7-01, #4#, @ 2880 ps Conf

0u

0c

4) Q t) E

16 13 T^ TvLSquare Root of Time in Minutes '» '» O Time in Minuter. v.** \* ^*^ CONSOLIDATION DATrA L-AP1B11--01-T-01, I$£Q 5760 ps Conf.

-10-*

0 0 -20 -

0c -30 - 4) Q ED -40 - ——

-50 -==

0 -B- -50 - 1: 240 .0 10 12 14 16 13 /M Square Root of Time in Minutes ^v~ D Time in Minutes CONSOLIDATION DATA \-\--\ ?oi5\«. L-AP'B11 -02-T-01, //5A, 9 '440 psf Conf. 0 -fi>——,-

0 0

0c *• ju) l*0- Q 0 £ 2o

60 )— -B-- ~ -26 - _i:o— 2-10 30 8 10 12 14 Square Root of Time in Minutes 0 lime in Minutes Volume Deflection in ec I I [ I I I t I I I I I I I 1 [ r CONSOLIDATION DATA '. /. 70) 5m L-AP1BI1-32--T-01 #20, @ 5760 psf Conf

-10 -

0 0 -20 - ——

c0 '+> J0) >4- -30 —— a0 Eo 2o -40 -

-50 ————

-60 - Square Root of Time in Minutes Time in Minutes i I i 1 i I (t CONSOLIDATION TEST DATA APITMW9T-06 1.5i30

1.4130 ~

1.300 - c O 1.200 c5c o o 1.100 i

1.000 -

0.900 -

2.00 2.40 2..8C LOG PRESSURE n Pressure - psf Deflection in inches TIME READING DATA - .14 V)' APITMW9T-06 1600 psf _oad u.uuu -ir— \*r; — 0 i -t— - C.oo f -0.002 -I i \\ I -0.004 -A -0.006 - —— i1 —— i/i -0.008 -

• \ •~Jt\J I \S '\ -c • Q 0 1 0 - c f\ -t 'i \ O .012 - 14 .2 -0.014- -M0 k £ -0.016 -———— oo V *t — U.Ulo - n -0.020 - i-Aiv ^ ______— 1 -^ - •60.0 ^^~ ~~~-~ _ . -0.024 - b^ 240.( > -0.02•~\ /V%6 / ^ -| —— — 481 0.00 ^^•^ 4.00 8.00 12.00 16.00 20.00 t0015" " CAI ixnr Rr\nr «- TIKJC T 5 D Time in Minutes TIME READING DATA APITMW9T-06 3200 psf _oad 0.000 - -0.002 0-

I0) £ 0 C

C 0 0 0

16.00 20.00 SQUARE ROOT cr TIME n Time in Minutes 1 ( i ( I 1 H-Jr- i TIME READING DATA APITMW9T-06 6400 psf _oad

C-

V) 4) JC c c o o a«

240.0

12.00 16.00 20.00 SQUARE ROOT cr TIME D Time in Minules 1 I i i I J I I (1 TIME READING DATA APITMW9T-06 12800 psf Load 0.000

n JLo 0 C

C 0 *• 0)

>.0 -0.050 - 0.00 4.00 8.00 12.00 16.00 20.00 «>.»•* SQUARE ROOT cr TIME D Time in Minutes GRADATION TEST DATA TERP IACHEM LABORATORIES, INC. LAS TO. lABwn OlOfiOl PAT TTTnoMT » r~irr , 12 S60 W. Cedar Drive, Suite 20S CUE ^^• MATF? WASTE ^ LANK3JEC1 D « Lakewood, Colorado 80228 FEA TUR f APACHE TAILINGtoJECTS N0.*. booc; (303) 9S9-5L59 Fac (303) 980-6157 SAM PUE NO. LO DJ1TETEST £0 p L-AP 1 B40^T-01 -9 1 1 74 GRAIN SIZE ANALYSIS T U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS ICO 3" 1.5" 3/4" 3/8" 4 8 1€ 30 5O ICO 2 DO i 1 |l H 1 fi S » 1 III i I ll 1 N4^II _ ' III T 90 ll ^* ll h!l HH 1 ll . ll \ "1 1 ii i s S T ill H 1 1 ll k ll 70 i 1 ll 1 ll ^ I i 1 1 i ll 1 I ^ 1 6O i 1 ll \ III! 1 1 \ H i 1 \ 1 til 1 1 1 40 hi il 1 i, \ 1 lii ll ll 1 30 Ik 1 1 ll Ii 1 1 1 | 1 1 ji 1 1 I 20 i 1 II 1 I \ U 1 II II i \ 10 H II II 1 1 \\ 1i in 1 11 III \\\ r i O CO•— — KD 1.0 - 0. 0.01 O.OOI rtPAiiu <;ITP iw un i lurTfBt; GRAVEL | SAND 1 COARSE FINS fcCARSSJ MEDIUM | FINSILT OR CLAEY 1 LIQUID LlMf PLASTICITY INDEX DESCRIPTION uses 1 U.S. Panic* P«rc«nl U.S. Par-tic* Pwc«nt U.S. Porllci* Ft r tent PorticU Porcenl Si«v« Siz«rrvr> F1n«r SWv« Siz« nvT* Fin«f Sl«v« Slz« mnr Finer Sin mm Finer 1 V4" I9.0O 30 .590 84 .019 VB" 9.50 50 .297 73 .009 5.0" 126.7 4 4.750 100 100 .149 60 .005 1 3.0" 76.0 8 2.330 92 200 .074 41 .002 1 1.5' 38.0 16 1.190 89 —— .037 .001 TERRACHEM LABORATORIES, INC LAB TCT. i AflNO. 010601 12S60 W. Cedar Drive, Suite 208 CUEKfTWATR W^^TF *• I ANTt PROJECTr&T TTAUMTA rirt I*T. Lakewood, Colorado 80228 rFATuRF APACHE TAILINGS ,*,,3JEC TN 0.. Pbooc: (303) 989-S1S9 Par (303) 580-6157 SAWPl-E NO. 2.0 QAFET- E :sr ED L-APB407S-01-911026 •WW^^ GRAIN SIZE ANALYSIS ^•w U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" .5" 3/4" 3/8" 4 8 16 3O 50 100 2CO _!00 11 1 1 I -^ 1 III II 1 1 * J 1 I 90 III ll Illll II1 A TTT 1 ll 1 1 - 70 niilll 1 60 il 1 1 \ MM fl 1 i 50 i \ nil I1 *\ Hi 1 H 1 II A\ MM li 1 ll ll \ \ 20 iti 1 II1 ll i \\ 10 lit "vj H .ll 1 H ll ll 1 1i ll 0 CO———————— 1 — - ——————————————————————————————————————————————————II XD 1.0 i - 0. n 0.0— 1 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL | SAND COARSFINE fcCritfS£E MEDIU| FINE MSILT OR |CLAY

LIQUID LIMIT PLASTICITY INDEX - DESCRIPTION uses U.S. Port'cia Ptrcanl US. Par-lie* P«rc«nl U.S. For lick Ptrcent Particlt Percent Si«v< Siztmm Finer SWv« Sir« nvn Fir>«r Sl«v« Sll« rrtr\ Firwr Slnnwn Fin«r 3/4" 19.00 30 .590 92 .019 V8" 9.50 50 .297 ss .009 5.0" 126.7 4 4.75O !OO .149 '24 .005 3.0" 76.0 8 2.380 100 200 .074 11 .002 1.3' 38.0 16 1.190 99 — .037 .001 TE RRACHEM LABORATORIES, INC. LAB TCT. ,ARNO 010601 1 12S60 W. Cedar Drive, Suite 20S CUEKTiZAT rc UA<;TF & TAND PROJFCT r AT T-CTIDVTT A ,-,* -, Lakewood, Colorado 80228 FEA- ruR F APACHE TAILINGS ECTh^0^ 3-0 QATE Fbooc: (303) 9SO-5159 Fuc (303) 98CU6157 SAMPUE NO. TEST £D LAP1BAIOS-01-91102A GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 1 ICO 3" .5" 3/4" 3/8" 4 8 16 30 50 100 200 1 I III 1 1 1 ll \ 1 IIItin ! 1 ii> 1 1 1 90 till 1 -4r II 1 1 1 k 80 Ilik 1 1 1 1 ll \ —^ Ilil 70 liil 1 is V 60 ll I 1 1 y 50 1 1 II 1 1 1 S V 40 1 II ll y Ilil 1 ll y 30 It 1 II \ M^ IH 1 1 II ll 20 \ 11 1 ll 1 I II 1 ll 1 1 •— W l 11 10 It II nr in ll x 'Hi 1 H ii i 1 1 1 *•- 03 JO i H 1.0 • O.II I 0.01 O.COI GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE ITTA RSE\ MEDIUM FINE SiLT OR CLAY iM LIQUID LIMIT 39 PLASTICITY INDEX 14

•W OESOR1? TION uses U.S. Parlida P«rc«nl us. Porticia Pvcant U.S. Porllc k Pircont Porlicl* Pereon Sitv« Siltnvn Flnar SWv« Sot mrr F'lMf Sltv« Siz< mtr Fin«f Slrtffwr Fin«r 2/4" I9.0O 30 .590 .019 100 3/S" 9.50 50 .297 .009 90 5.0" 126.7 4 4.75O 100 .149 .005 76 3.0" 76.0 8 2.380 200 .074 .002 49 1.5" 38.0 16 .190 —— .037 .00 30 1 TERRACHEM LABORATORIES, INC. LAS TCL iAflnn nin<;ni 12S60 VV. Cedar Drive, Suite 208 CLIENT UATFR, WASTF f. T «,yT) PROJECT CAT.TTORNTA flUn ~ Lakewood, Colorado 80228 FEATURE APACHE TAILINGS PROJECT NO Pbooc; (303) 9S9-5L59 Tin (3CD) 980-4157 SAMPLE NO. 4.0 QATE: TF llll III 1 1 90 liii ll III V it II 11 1 8O Ii M X 1 1 Iln 1 1 1 T 5 ll 1 1 Hi! 1 \ 70 Hi! II \ 1 1 ii i 60 \ 1 ll r~ 1 | 50 ii II \ 1 III 1 1 \ ll \ 40 ii 1 1 \ 1 ii II \ 1 30 Hi ll ll 1 N 5 II II II 1 1 Is 20 I II [1 1 r"*"4^. h ll II \ ^T^ 4 4 10 It II ll 1 \ "**«*^ III 1! 1 II III 1 IIHI 1 'I "^T^. • CO 10 1.0 • 0. 0.01 O.OOi GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE OCARSQ M£DIUM FINE SILT OR CLAY

LIQUID LIMIT PLASTICITY INDEX DESCRIPTION uses 1 U.S. ParticiB Percent as. Poetic* US. Porlick Ptrcont Panic l« Pereen t Si*v< Siz«nvn Finer SWv« Siz* nvn Firxr Sl«v« Sin nvr Fin«r Slztnv m Fin«r 1 V4" 19.00 3O .590 92 .019 14 1 3/S" 9.50 50 .297 64 .009 9.8 5.0" 126.7 4 4.75O IOO .149 35 .005 7.8 1 3.0" 76.0 8 2.380 100 200 .074 19 .002 3.9 1.5" 38.0 16 1.190 99 —— .037 16 .00 1.9 LA8 TCL mown mn*;ni TERRACHEM LABORATORIES, INC . CUE 1 12S60 W. Cedar Drive, Suite 208 KT WASTF. WATFB R T 4MT> PftOJECTrAT-TFOPNT A PTTT rr Lakc\vood, Colorado 80228 FEAruRIE APACHE TAILINGS p«n.)erT un Pbooc: (303) 5S9-5LS9 Pax (303) 9SQ-61S7 SAM PLE NO. 5-0 QATT TESTED — T L-AP1B502T-01-9 11023 i GRAIN SIZE ANALYSIS "•^ ^ U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" 1 5" 3/4" 3/8" 4 8 16 30 50 100 2(X) 100 III ' 1 | ^ ^ i II ' 90 ll ll ll 1 TII T ll i Mlll V^«v\i 1 1 6O liL ' \ 11 1 » 70 111! H I \l — N if n TTiT 1 il Vi I I I 60 Hiiit ll 1 1 *, iSii 1 Ili! Il — « 40 ii ilIIIl ! I H ilH 1 1 30 Hi 1 II 1 II 1 20 ii 1 IIiI 1 HH 1 «•* - i I 11 1 II 10 ii II II in H Mi 1 1 11 ll CO KD 1.0 - 0. mi! i 0.0i 1 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE fctW?S3 MEDIUM FINE SILT OR CLAY

LIQUID LIMIT PLASTICITY INDEX DESCRIPTION uses 1 U.S. Parlicie Ptrcenl as. PorticA U.S. PorllcW P»rCant Porticl< i P«rcenl Si«v« Siztrrvm Flnar SWv« Sii« nv n Fifvar Sltvt Sin nvn Firwr Slnmn t Fin«r 1 V4" I9.CO 30 .590 100 .019 —i V&" 9.50 50 .297 95 .009 5.0" 126.7 4 4.750 100 .143 82 .005 3.0" 76.0 8 2.380 200 .074 66 .002 1 1.5' 38.0 16 1.190 — .037 .001

c r r • i o c \.)f TERRACHEM LABORATORIES, INC. LAB TCL ... LAB NO. 010601 12S60 W. Cedar Drive, Suite 20S cu£>rr UATFR UA1TV f, LAND PROJECT CM TTY1PHT A rm C Lakewood, Colorado 80223 FEATUR F APACHE TAILINGS PR, 3JECT N 0. Pbooc: (303) 9S9-5LS9 Fac (303) 9SW157 SAMPLE NO 6.0 DAITTES' T ED L-AP1B507S-01-91102 2 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" I 5" 3/4" 3/8" 4 8 ft 3O 50 100 2CD* -100 ¥ 1 i i h i 1 1 Hill II 1 li till II 90 tillll li i n hi GO 1llil llii l 1 i ~ 70 in ni Ilii 60 1 il i li li I i ii i 40 i i i i i i 1 M» li III i li 1 n 20 \1 lii i lli j| 1 "1 10 J 11 H i IK ii li 1 1 1 1 1 — "C0 Oil i n 1i0 h 1.0 - O.imI 0.01 0.00! rCAIW

LIQUID LIMIT PLASTICITY INDEX — DESCRIPTION uses U.S. Partic* Ptrcent as. Porticfc Pwc«n| as. Portlcfc Ptrtont Porticli Ps re ant Si«v« Siitrrvr^ Fln«r SWv« Sirt mm Fin«r Sitv« Sin mm Fin«r Slrtfivn Finar V4" I9.0O 30 .590 .019 3/8" 9.50 50 .297 .009 5.0" 126.7 4 4.750 ICO .149 .005 3.0" 76.0 8 2.380 200 .074 100 .002 1.5* 38.0 16 1.190 —— .037 .001 TERRACHEM LABORATORIES, INC. LAS TCL LAB NO. 010601 12860 W. Cedar Drive, Suite 208 CLirNTUATKB. VASTF f. T AWT1 PROJECT TAT T-LT.OMT A ^,r, ^ -, ~ Lakewood, Colorado 8022S FEAT ruHE APACHE TAILINGS pfl(V JECTN 0.. PLE NO. 2.0 QATE Pbooc: (303) 9SJ-5L59 Far (303) 980-6157 SAM TEST EO L-AP1B602T-01-911022 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS

3" 11 5" 3/4" 3/8{ " 4 8 16 30 50 100 2D>4 > iTr"""II " —— "" II \ ! 90 ll 1 \ IIII ^•* un- 1 \ tIII it I1 1 lliIllTl 1 _ 70 Illl ll ! IT 6O 1 fl i I) ll •M II 1 1 1 II 50 III 1 ~ IP ft ^ - 40TFT II I III 1 1 1 1 ^X, ,0 Hi ll ll 1 1 •«• Illl ll jl 1 1 1 x. 1 ll 1 PX_^y 20 m llii ll 1ll ^ 10 in il ll 1 i s H i I H H II III ill Y ••B 1 II ll 1 I KX) 10 1.0 - 0. hit 0.01 r r=0.001 i GRAIN SIZE IN MILLIMETERS GRAVEL SAND 1 COARSE FINE CC6RSE\ MEDIUM FINE SILT OR CLAY T LIQUID LIMIT PLASTICITY INDEX NON-PLASTIC

tit >ES( :HI?TION uses U.S. Porte* Ptrcant as. Pwcant U.S. Porlki* Parlicl i Percent Si«v« Sinmm Finer SWy< Siz« rrvr\ Fir^r Sltv« Sin mm Finer Slnmn i Finer 1' V4" I9.0O 30 .590 99 .019 28 -rr vs" 9.50 50 .297 96 .009 19 5.0" 126.7 4 4.75O 100 .149 64 .005 5.4 » 3.0" 76.0 8 2.380 200 .074 40 .002 4.0 1[ 1.5' 38.0 16 1.190 100 —— .037 36 .00 2.7 1 TERRACHEM LABORATORIES, INC. I.A8 TT.T. LAB NO. inifini 12S60 W. Cedar Drive, Suite 20-; CL!E UATFP UA<;TTT f. T AWTI PROJECT PAT T-pnowr A r*,n ^ Lakewood, Colorado 80223 FUTURE APACHE TAILINGS wnjFcr NO Pbooc.- (303) 9S9-5159 Far (303) 980-6157 SAMPLE NO. 8.0 QATE TESTED 1 L-AP1B608T-01-911022 f——— GRAIN SIZE ANALYSIS 1 U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" .5" 3/4" 3/8" 4 8 16 30 50 ICO 2(DO 1 ico 1 1 Hi! II •*« ' II ITT ——— ^^ —— ' 90 Ilil ll \ IIiii in ll i 1 &O li 1 ii lit 1 1 1 1 V\" 7 In 1 1 II 1 ° ijtl 1 \ M 1 III 1 ll \ 6O Hi \t- Uo ilIIl I >s^ 4 ill 111 [•- S^ 1 ^ ill II \ In I \ 1 - . 30l!i 1 1 ll \ 1 | | ll \ \ 20 i i S Ij_T 1 ll >

LIQUID LIMIT PLASTICITY INDEX OESCH1? TION uses U.S. PorticiB Percent US. Porlicie U.S. Porllde Percent Panic e Percent Sieve Sixerrvn Finer SWvt Sir* nvn r \r*& r Sieve Size mrr Fin«r r> Finer V4" 19.00 30 .590 99 .019 33 3/8" 9.50 50 .297 96 .009 18 3.0" 126.7 4 4.750 100 .149 83 .005 12 3.0" 76.0 e 2.380 200 .074 56 .002 7.0 1 5' 38.0 16 1.190 100 —— .037 A3 .00 A. 6 LA8 TERI IA,C TCT. L AB NO. 010601 :HEM LABORATORIES, INC . CUE NT UATFR, UASTF X T.AWTl PROJECT TATTt:npwT HTTT < R 12 S<;o W. Cedar Drive, Suite 208 ft I.a kewood, Colorado S0223 FEAniRF APACHE TAILINGS p«o.IPcT NO r•bo oc : (303) 9S9-5L59 Par (303) 980-6157 SAW PLE NO. 9.0 DATT TESTED L-AP1B802T-0 1-91 1022 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" 5" 3/4" 3/8" 4 8 >6 30 5O ICO 2DO ICO 1 ^ ] IBM* T II HI 1 III 1 ll 1 90 III! TT"'-\ - BOmi 1 T ~1 \\ lal 1 II \ 70 li ^ ^•i i '^ s 60 Hit ^ li \^ T in \ 50 hit \ - 40HIi i 1 \ |I 30 in i i in ll ll A\\ 1 1 1 20 n II 1 II 1 i II 1 V i \ 1 i |s 7 10 Sii II H 1 •I li H 1 11 11 Illlll | _. CX) JO • 1.0 - 0. 0.0in 1 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL SAND T COARSE 1 FINE I MEDIUM FINE SILT OR CLAY T lJQUID LIMIT PLASTICITY INDEX cASCRIPTION uses U.S. Porte* P«rc«nt US. Peptic* US. Portlcit Percent Portic l« Percont Si«v< Siz«nvn Flnar Sir* ftvr Fir*r Sl«v« Slz« rrvr Fin«r Sin (TVm Fin«r [ 3/4" I9.OO 30 .590 100 .019 54 i* 3/S" 9.50 50 .297 97 .009 26 5 .0" 126.7 4 4.75O 100 .149 84 .003 10 - 3 .0" 76.0 8 2.380 200 .074 68 .002 9' 1 .5" 38.0 16 1.190 —— .037 62 .001 9 r TERRACHEM LABORATORIES, INC. LAB Tri. LAS NO. mnfim _ 12S60 W. Cedar Drive, Suite 208 CUENT UATP-O UACTV i T A MT> PROJECT r AT T1Tni>MT A ™TT Lakcwood, Colorado 80228 FEATURAPACHE TAILINGS Et»« n. JEC N 0 Pbooc: (303) 989-5 L59 Fac (303) 960-6157 SAMPLE NO. 10.0 OATETE ST PD L-AP1B806S-01 - II 90 III ll 1 s ll il 'II ll I tXJ l| 1 ll 1 \ 1 -70 ll v 1 ll II1 \ 60 111 1 ^ »WMf 11 1 1 1 1 k SO I 1 I ll 1 ——— -\ 1 ll V 1 III ll lIlI S| *•«• ll 1 hHii! 1 1 20 ll II ll 1 I lil i i 11 II 1 i to ti III ; 11 Hi II ll II H 1 II ll cXD ll IO ll 1.0 - O.I 0.01 0.00! GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE COURSE] MEDIUM FINE SILT OR CLAY

LIQUID LIMIT PLASTICITY INDEX DESCRIPTION uses U.S. Partic* P«rc«nl US. Porlicfc P»rcant U.S. Portlcfe Ptrtont ParticU Porcent Sitv« Siz«mm F1n«r SWv« Sir* nvn Fir*r Sl*v« SU« mrr Firwr Sin mm Finer 3/4" I9.0O 30 .590 99 .019 3/8" 9.50 50 .297 82 .009 5.0" 126.7 4 4.750 100 .149 53 .005 3.0" 76.0 8 2.380 200 .074 30 .002 1.3' 38.0 16 1.190 100 — .037 .001 TERRACHEM LABORATORIES, INC. UA8 rrr LAB no mn«ni 12860 W. Cedar Drive, Suite 208 CUENT UATFD UACTTT r TANT> PHOJFfT rATTTrtt>MT« (~TTT t Lakcwood, Colorado 80228 FFATilRF APACHE TAILINGS PR, OJEQ 'NO. SAMPLE NO. 11.0 DAPET- E STEO Pbooc: (303) 985-5159 Fac (303) 980-6157 L-AP1B810S-01911023 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" .5" 3/<" 3/8" 4 8 re 30 50 100 2DO 100 1 M H ll I •""4 HI i ll ll ll SO ll ll \l CO 1 1 1 1 \ 11 1 1 ll N 1 70 1 1 1 l\ 1 ll II Ss 60 III II • ll 1 II ^i Mil 1 \ 50 II J 1 \l 40 III 1 V 1 III ll \ 1 lit 1 ll 1 \ -1 'O ll 1 1 1 1 1 1 v 1 20 ll I 1 ll 1 IX 11 1 1 T 1 T^ 1 10 111 1 ll nr | t^^^. l 111 1 II li ll II 1 1 III It Ml 1 ! III 1 1 0 CO————— 10 1.0 - 0.1 0.01 O.OOi GRAIN SIZE IN MILLIMETERS GRAVEL SAND SILT OR CLAY COARSE FINE fc X*KS£ ' MEDIUM FINE

Ll QUID LIMIT 33 PLASTICITY INDEX 11 DESCRIPTION uses U.S. Porticfc P«rc«nl US. Porlida Pwc«nt U.S. Portlcfc PtrCont ParticU Perceal Sitv< Siztmm Finer SWv« Six* nvn Fif*r Sltv« Slz« rwr Firwr Slzt nvn Fin«r V4" 19.00 30 .590 100 .019 40 3/S" 9.50 50 .297 99 .009 29 5.0" 126.7 4 4.750 100 .149 96 .005 22 3.0" 76.0 8 2.380 200 .074 75 .002 13 1.5" 38.0 16 1.190 — .037 66 .001 11

FiGUPF NO. T TERRACHEM LABORATORIES, INC. LAB TCL L A8 NO 010601 US6Q W. Cedar Drive, Suite 208 CLIENT UAT-RR UA-5TV X. T AWn PROJECT PAT TrrmMT A — Lakcwood, Colorado 80228 MATURE APACH3JECE1 'NOTAILING. S ^ Pbooc; (303) 989-5 L59 Par (303) 96O4LS7 SAMPLE NO. 12.0 DArETE STEO L-AP1B902T-01-911021 T GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS T 3" .5" 3/<" 3/8" 4 & \6 30 50 100 2(DO ICO 1 II 1 ' I" i II 1 M i T Tt" X 1 90 ll II 1 1 i V III ll i i ll "T SO III 1 1 ll 1 il H \ 1 till 1 1 1 1 Ii s 1 1 N S 70 W i ( v III! 1 1 I i 1 s 1 1 ! i 1 \ eo HI! 1 i ii1 1 ll i \% 1 1 » 1 ll i \ ii 1 II i \ 1 i ll 1 II i \ 1 30 ll 1 1 Ii y 1 -r 1 1 1 \ IH i1 1 II 1 ll 1 I 20 s 1 Ii M >. 1 1 1 II I ii II T= =R__ • ! n il II II \ II 1 1 II Ii H III | i ll ii ll 1 i 0 — SO 1.0 - O.II 1 0.01 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL SAND 1 COARSE | FINOCARSEEJ MEDIUM FINE SILT OR CLAY LIQUID LIMIT PLASTICITY INDEX 1 DESCRIPTION uses 1 U.S. ftart'c* P«rcenl US. Porlicfe Pw«n| U.S. Portlcfc Percent PorlicU Pare en! Sicvi Siz«nvn Fln«r SWv« Sir* irvn Firar Sl«v« Slz« trtr\ Flrvar Sin mm Finer 1 V4" 19.0O 3O ,590 98 .019 53 ~r ^5" 9.50 50 .297 96 .009 19 5.0" I26.7 4 4.75O 100 .149 90 .005 16 1 3.0" 76.0 8 2,380 100 200 .074 75 .002 16 1 I.5' 38.0 16 1.190 99 — .037 .001 TERRACHEM LABORATORIES, INC. LAB TCT, i e, 8NC y oiofim 12860 W. Cedar Drive, Suite 208 CUENT WATFT? UA<;TF s. T AMT> PROJFCT r HAT TTVM>«T . ^,-r, Lakewood, Colorado 80228 FFATURF APACHOJ£( Errso TAILING. S ^ SAMPLE NO. 13.0 fVfTEl T E5TEO Pbooc: (303) 98%5159 Far (303) 9S&4157 L-APje^ogT-ol-^llozi l GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS X) 1 100 3" .5" 3/4" 3/8" 4 8 116 3O 50 100 2( |l 1 1 1 1 ^ 90 III II 1 1 III ll 1 1 m \ 1 II —— 1 1 \\ ll 1 ll ^, 1 7O till I 1 III II ll i K \ 1 60 1 I 1 \ \ 1 1 1 s 50 ll 1 1 1 1 s 1i 40 1 1 1 Kv fc. tl ll II 1 ll II ll 1 •1 \\ III II 1 ll I 20 J II III 1 | 1 1 1 I! 1 1 II 1 10 it II 1 1 II 111 II ll 1 Hi II 1 ll ll III \ \ \ 0 00—— 10 1.0 - 0. \ 0.01 0.001 ftOAIW CI7F IU Ull I IUFTFD<; GRAVEL SAND COARSE FINE COXRSSJ MEDIUM FINE SILT OR CLAY A4 LIQUID PLASTICITY INDEX 20 DESCRIPTION uses U.S. Pa rt eta P«rc«nl US. Porticfc P*r«nl For tick Ptrcenl PorticI* Perconl Sitvt Siztnvn Finer SWv« Sir* mm Fir*r Sltvas.« Sin tnr Firwr Slzt tnm Fin«r V4" 19.00 30 .590 .019 97 3/S" 9.50 50 .297 .009 78 5.0" 126.7 4 4.750 100 .149 .005 63 3.0" 76.0 8 2.380 200 .074 .002 41 1.5' 38.0 16 1.190 — .037 100 .001 30 FIGURE: NO. TE RRACHEM LABORATORIES, INC. UA8 TCT. IARNO 010601 CUENT«ATFT? UA<5TF K. T AWL PROJECT fAT.TVnPNTA *-TTT , 12860 W. Cedar Drive, Suite 208 t Lakewood, Colorado 80228 FEATURE APACHE TAILINGS pq, DJECTN 0. . Ptxxxu (303) 989-5159 Pax (303) 9SW157 SAMPLE NO. 14 QArtTEST FD L-AP1B1002T-01-911022 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" 5" 3/<" 3/8" 4 8 16 30 5O 100 2CO _00 TOT 1 I M I i I 1 90 III! 1 i 1 1 ll 1 1 -^ I 1 1 1 i \i III! 1 1 i y.•**->. 1 1 1 •~ • 1 — 7O i •k > V ll 1 1 vI II 60 1 1 i \ 1! 1 i 50 Ii 1 1 i \\ 1 I III I i 111 i i \k III 1 i \ III II i 1 \ ll II | I ss 1 ll | | ^. II 20 | •\ 1 II |)i |1 \ 1 10 !l 11 I i \ 5 i i V H III II HI 1 1 TT r-r-4- — » °00 K> 1.0 - O.I II 0.01 0.001 r:DAt»J CI7C IkJ VJII 1 IUCTCDC GRAVEL SAND COARSE FINE tOXRSSJ MEDIUM FINE SILT OR CLAY

LIQUID LIMIT PLASTICITY INDEX — DESCRIPTION uses U.S. Panic* Ptrcent U.S. Pa-ticfe US. Portlck PtrCant Pariiclt Porcenl Si«vl Sizerrwn Finer SWv« Siw nvn ^Slrv« Sin mrr Fin«f Strtnvn Fin«r 3/4" 19.00 30 .590 72 .019 22 VS" 9.50 50 .297 67 .009 5 5.0" 126.7 < 4.75O 100 100 .149 55 .005 4 3.0" 76.0 8 2,380 77 200 .074 40 .002 2 1.5' 38.0 16 1.190 75 — .037 34 .001 TERJUCHEM LABORATORIES, INC. LAS TCL 1 AH NO 010601 12860 W. Cedar Drive, Suite 208 CUENTWATKR, UASTF f. T Am Pf^ JECI ' CALITQBNTA rm ,"l Lakewood, Colorado 8022S FFATURF APACHE TAILINGS pJEC^ ! r KQ Pbooc; (3CD) 9SU-S 159 I'ax: (303) 98CW157 SAWPUE NO. 15.0 OAETTE ST ^D GRAIN SIZE ANALYSIS ^ U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS _ ICO 5" 3/4" 3/8" 4 8 16 3O 5O 100 2(X) till 1 1 H l "S s. 1 III ll ! l> 9O III i ii II i [ 80 l| 1 II 1 \ 11 III 1 II \ l1l 1 1 ill! 1 II i II 1 1 ll H rr— r° 60 li 1 ii II } ,0 111! ll ft Uil II Hi 1 ll II 1 1 <° It II 11 1 1 3O In 1 li 1 E5: 1 19 II 1 fl 20 1 11 li 1 H IIP ^ 10 I 1 II Ml I s H 1 II i III \ "V »«s. III Ml II 1 1 i KDO 10 1.0 - 0. r i >- 0.0— 1 0.00 1 GRAIN SIZE IN MILLIMETERS GRAVEL SANO COARSE COARSE| }FIN MEDIUM E FINE SILT OR CLAY

1.101 JIO LIMIT PLASTICITY INDEX C>ESC :RI? Tl ON uses U.S. Portcta Ptrcant as. Particfc Pw&anl U.S. Portick Ptrcant Parlicl « Psrcen 1 Si«vt Sijtrrvn Finer SUv« Sirt rrvr\ Firxr Sl«v« SU« mrr Fin*- Slnmr n Fin«r 3/4" I9.0O 30 .590 99 .019 3 vs" 9.50 50 .297 94 .009 1 5.0" 126.7 4 4.7SO 100 .149 58 .005 1 3.0" 76.0 8 2.380 200 .074 18 .002 .5' 38.0 16 I.I9O 100 — .037 8 .00 Tl ERRACHEM LABORATORIES, INC. LAS TPT LAB NO. _ ninfini 12S60 W. Cedar Drive, Suite 208 CLIENT WATER, WASTE & LAND ppo.,Frr CALIFORNIA GULC51 Lakewood, Colorado 80228 FFATURE APACHE TAILINGS PROv ECTN 0. Pbooc: (303) 98^5 159 Fin (303) 980-6157 SAMPLE NO. 16.0 DATE TEST to -*> T-APnunnos-ni- -01107-? f— GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 1 3" 1.5" 3/4" 3/8" 4 8 16 30 50 100 2(X) ,00- i 1 ll 1 1 1 90 - cm H ~I BO - II — 70 • 1 60 • 50 • 40 ll It . 30 ll 1 i 1 20 • i 10 •lit 1! II 1 COli t KD 1.0 - 0. 0.01 O.OOi GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE COiRSEJ MEDIUM FINE SILT OR CLAY

LIQUID LIMIT PLASTICITY INDEX DESCRIPTION uses U.S. Par tick Ptrcanl US. Porl'tcH Pwcanl U.S. Pa-tlck Ptreont ParticU Percan 1 Si«v« Siztmm Finer Sl«v« Sizt mm Fir*r Sl«v« Slz« mrr Flnar Slztnur i Finer

1 3/4" I9.0O 30 .590 .019 -1 3/8" 9.50 50 .297 .009 5.0" 126.7 4 4.750 IOO .149 .005 3.0" 76.O 8 2.380 200 .074 100 .002 1 1.5' 38.0 16 t.190 —— .037 .001 1 TCL , 010601 TERRACHEM U J30RATORIES, INC LAB ABHn 12860 W. Ceds (r Drive, Suite 208 CLJFX/T WATER, WASTE & LAND p^rrr CALIFORNIA GULC Lakewood, Colorado 80228 FEATUR F APACHE TAILINGS p«n ECTN 0- SAMPLE NO. 17.0 DATTESF T ED Pbooc: (303) 98W 159 FIE (303) 980-6157 L-AP1B1010S-01-911022 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 3" .5" 3/4" 3/8" 4 8 16 3O 50 100 2(DO ICO - 1 [ I i ~ "f-C, 90 -i | 1 ^ 1 1 ^ JT \ 1 1 1 \ 70 - \ 60 - \ \\ 50 - y S < 40 - y SJ 30 • ^x N ^^ 20 - II \ ll 10 - H II 1 III 1 1! 1 0DO 10 1.0 • O.Ill 0.01 0.00 1 GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE | FINQDAfiSSEI MEDIUM FINE SILT OR CLAY

LIO U10 LIMIT 32 PLASTICITY INDEX 9 DCS CHIPTION uses U.S. Portic* Percent US, Porticie Percent US. Portlde PtrCant Porticli Percent Sieve Sizenvn Finer Size mm Finer Sieve Size mrn Finer Slztftvr i Finer 3/4" I9.0O 30 .590 .019 70 3/S" 9.50 50 .297 .009 AS 5.0" 126.7 4 4.750 100 .149 100 .005 36 3.0" 76.0 8 2,380 200 .074 ' 99 .002 22 1.5' 38.0 16 I.I9O — .037 95 .00 16

\ TCL 010601 1 Tl SRRACHEM LABORATORIES, INC LAB lAflNQ 12860 W. Cedar Drive, Suite 208 CUE •wr WATER, WASTE & LAND PROJECT CALIFORNIA GULC1 Lakewood, Colorado 80228 PEA TUR f APACRE TAILINGS par DJECTN 0 SAM Pt£ NO IRA DA' PETEST •EO 01-17-Q7 Fbooc: (303) 989-2159 Fax (303) 9SW1S7 L APB906T-01-911021 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVHYDROMETEE SIZER ANALYSIS S | 3" 1.5" 3/4" 3/8" 4 8 J6 30 50 100 200 r 100- [ •I* M ^ 1 II I ™—r- ••• •» MMBM ll \ [ 90 - 1 ll ' i art V 1 °° 1 1 1 \^ 1 \ f'°60 : - \> \ 1 \ 1 v>: 1 1 >v 1 40 - 1 !1 \ 1 l \ 30 - ll i v 1 ll k \ \ %*s 20 - \ ll i N, \ 1 i S, | ,0N - i III I 1 1 H ll It 1 00 KD 1.0 - 0.1 li 0.01 0.001 HPAIW QI7P IW Mil 1 IUPTFS c; GRAVEL SAND 1 • COARSE FINE coarse MEDIUM FINE SILT OR CLAY LIQUID LIMIT 19 PLASTICITY INDEX 1 DESCRIPTION uses 1 U.S. Poetic* Ptrcent US. Portia* Pwcanl US. Portldt PtrCant Portick Percenl Si«v« Siztnvn Finar SWvc Sir* mm Fir«r Sltv« Slz« nvr Fif>«f Sir* mm Finer 1 3/4" I9.0O 3O .590 98 .019 46 -I 3/8" 9.50 50 .297 97 .009 29 5.0" 126.7 4 4.750 IOO .149 97 .005 21 3.0" 76.0 8 2.380 100 200 .074 ' 87 .002 12 1 1.5" 38.0 16 — 1 1.190 99 .037 63 .001 | ERRACHETl M LABORATORIES, INC LAB TCL LA8NO. 0106°1 12860 W. Cedar Drive, Suite 208 CLIENT WATER, WASTE & LAND pp^^rjCALIFORNIA GULCI Lakewood, Colorado 80228 FEATURE APACHE TAILINGS PRCk >ECTN 0 SAMPLE NO. 18C DATE TEST Fn 01-12-92 ' Pbooc: (303) 98SkSL59 Fix: (3CD) 960-6157 L-AP1B906T-01-911021 1 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 1 3" 1.5" 3/<" 3/8" 4 8 J6 30 50 100 2 TCL 010601 1 TERRACHEM LABORATORIES, INC. LAB |AflNQ 12860 W. Cedar Drive, Suite 208 CUEWT WATER, WASTE & LAND pftojprr CALIFORNIA GULCI — Lakewood, Colorado 80228 FEATURE" APACHE TAILINGS PROECT. N 0. . SAMPLE NO. 19A DATE.TEST ED 17 ™ 0] Fbooc: (303) 98^SLS9 Far (303) 9SW157 L-AP1B1 10 IT-01-91 1024 GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS 1 3" .5" 3/4" 3/8" 4 8 16 30 50 100 2(DO 100 1 1 r- » 1 ll -\ 90 ll \ 0ft/*0\ 1 V 1| 1 \ ll \ 1 70 1 1 60 1 A- 50 | \ II \ III 1 > 40 ll \ 30 ll C Illl 1 \ ll • Vi 20 1 1 1 1 1 1 1 s\^ i II i "Vy - 10 T ll \ \ i >«, Mil 1 II 1 1 ! o 00. —————— _ K3 1.0 • O.I 0.01 O.COI GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE CCW& : MEDIUM FINE SILT OR CLAY

LIO UID LIMIT PLASTICITY INDEX OES CHIPTION uses U.S. Porte* Percent US. Porticie Percant U.S. Portkde PerCant Portict* Percent Siev« Size mm Finer SWve Size nvn Finer Steve Size rwr Firwr Slzenur Finer 1 V4" 19.00 30 .590 .019 83 3/S" 9.50 50 .297 .009 57 5.0" 126.7 4 4.750 .149 .005 35 too •••** 1 3.0" 76.O 8 2.380 200 .074 "" 100 .002 14 1.5' 38.0 16 1.190 — .037 99 .001 7.3 1 LAB TCL LAB NO 01°60l ~[ T3ERRACHEM LABORATORIES, INC WATER 12860 W. Cedar Drive, Suite 208 ciiFWT . WASTE & LAND pfi^.crr CALIFORNIA GULC1 Lakewood, Colorado 80228 FEATURE APACHE TAILINGS p«rL IECTN 0. SAMPl^ NO. 20 B DATE TEST ED 12-30-91 Pbooc: (303) 96W159 Fac (303) 9KW157 L-AP1B1102T-01-911024 T GRAIN SIZE ANALYSIS U.S. STANDARD SIEVE SIZES HYDROMETER ANALYSIS I 3" .5" 3/4" 3/8" 4 8 J6 30 50 ' 100 2(DO 100 • 1 l 1 N 1 90 - 1 s \ e/«i 00 \ * 1 . 7O - " ^ 1 co- s \ SO - K\ . 40 - \ . V\ 3O - 1 il ll 20 • i t 10 •1 ljil B 0 ————————III — - — 00 10 1.0 - 0. 0.01 0.001 GRAIN SIZE IN MILLIMETERS GRAVEL SAND COARSE FINE ^•tff *^\OC : MEDIUM FINE SILT OR CLAY

LIQUID LIMIT 45 PLASTICITY INDEX .14 DESCRIPTION uses U.S. PorJicta Ptrctnt us. Par tic* Pwcant US. Ptreant Particl* P«rcan Si«v« Siztmm Finer SWv« Sir* nvn FifHf Sltv« SU« fTVT Firwr Slrt/Twn Fin«r V4" I9.0O 20 .590 .019 90 V8" 9.50 50 ,297 .009 77 5.0" 126.7 4 4.75O 100 .149 .005 65 3.0" 76.0 8 2.380 200 .074 ' " 100 .002 46 1.5' 38.0 16 1.190 —— .037 99 .00! 31 APPENDIX B MASTER SAMPLE LISTS APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST 0 0 S N A Q E E P U R A O O E T C / T C C R H Q E H 1 1 1 C Data Material Sample Impoundment Boring 1 Depth (ft) Sample 1 C E A E V Collected Type Type H M T N E 1 T D 0 N Main Surfec* L-AP1T01-01-910919 / 9/19/91 Tailing. Composite Surf tea L-AP1T02-01-910919 / a/ 19/91 Tailing* Compo.lte Surf act L-AP1T03-01-910919 / 9/19/91 Tailing* Compodte Surface L-AP1T01 01-910918 / / 09/19/91 Tailing. Compoalte Surfaca L-AP1T02-01-910919 / / 09/19/91 Tailing* Compo.lto Surface L-AP1T0301-910919 / / 09/19/91 Tailing* Compodte Surfaca L-AP1T-01-910919 / 09/19/91 Tailing* Compoalte L-AP1W-03-911021 / / 10/21/81 Water Rlns.lo L-AP1W 04-91 1021 / / 10/21/91 Water Trip Blank L-AP1W-03-911024 / / 10/24/91 Water Rlniat* L-AP1W-04 911024 / / 10/24/91 Water Trip Blank L-AP1W-04-910917 / / 9/17/91 Water Trip Blank L-AP1W-03-911022 / / 9/22/91 Water Rln.ate L-AP1W-04-911022 / / 9/22/91 Water Trip Blank L-AP1W-04-910924 / / 9/24/91 Water Trip Blank 0-2 L-AP1NCT-01-911021 / 10/21/91 Tailing* Composite 0-2 t-AP1NCT-02-811021 / / 10/21/91 Tailing* Compo.lt* 0-2 L-AP1NCT-MS-911021 / / 10/21/91 Tailing* Compo.lt* APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST ~" Q Q 3 H A O i E P u R A O O E T C / T C C R H Q E H 1 1 1 C Otta Mtteriil Sampli Impoundment Boring ' Depth (ft) Sample f c E A E V Collected Type Typa H M T N E 1 T 0 nO Main 0-2 L-AP1NCT-01-911021 J / 10/21/91 Tailing. Compoalta 0-2 L-AP2NCT-01-911029 / 10/29/91 Tallingi Compotha 0-2 L-AP2NCT-01-911029 / / 10/29/91 Tailing! Compoalta Downgradient 1 11-12 L-AP1B1018 01-810924 / 9/24/91 Subaoil Split Spoon 1 11-12 LAP1B1O18 01-810924 / / 8/24/81 Subaoll Split Spoon 1 16-17 L-AP1 B1 02S-01 -9 1 0924 J 9/24/91 Subaoil Split Spoon 1 16-17 L-AP1B1O2S-01 -910924 / / 9/24/91 Subaoll Split Spoon 1 21-22 L-AP1B1O3S-01-910824 / / 9/24/91 Subaoil Split Spoon Downgradlant 2 6-7 LAP1B202S 01 910917 / 9/17/91 Subaoll Split Spoon 2 6-7 L- API B2028 02-9 1 09 1 7 / / 9/17/91 Subaoll Split Spoon 2 6-7 L-AP1B2028-MS 810917 / / 9/17/91 Subaoll Split Spoon 2 10-10.6 L-AP1 B2038-O1 -91091 7 / / 9/17/91 Subaoll Split Spoon 2 16-17 L-AP1B204S01-910917 / / 9/17/91 Subaoll Split Spoon Downgradlant 3 4.8-6 L-AP1B3028-01-910917 / 9/17/91 Subaoll Split Spoon 3 10-11.6 L-AP1B3038 01-91091 7 / / 9/17/91 Bubaoll Split Spoon 3 16-17 L-AP1B304S-01-810817 / / 9/17/91 Bubaoll Split Spoon 3 20-21 L-A-P1B306S-01-910917 / J 9/17/91 Subaoll Split Spoon 3 24-24.3 L-AP1B306S-01-810917 X J 9/17/91 Subaoll Split Spoon APACHE TAILINGS TEST HOLI ASTE RSA dPLE LIST ______——— = :S-^=M ======___^ Q Q 8 N A Q E E P U R A o O E T C / T C C R H Q E H 1 1 1 C Data Malaria! Sample Impoundment Boring f Depth (ft) Sample 1 C E A E V Collactad Type Type H M T N E 1 T 0 O N Main 4 3.7-6 L-AP1B402T 01-91 1024 / 10/24/91 Talllnga Dry Core 4 3.76 L-APIB402T-01-911024 / / 10/24/91 Tailing! Dry Core 4 8.6-7 L-AP1B403T-01-911024 / 10/24/91 Talllnga Split Spoon 4 9-10 L-AP1B404T-01-91 1024 J / 10/24/91 Talllnga Dry Core 4 9-1O L-AP1B404T-O1-91 1024 / 10/24/91 Talllnga Dry Cora 4 14-16 L-AP1B406T-01-911024 / 10/24/91 Talllnga Dry Cora 4 14-16 L-AP1B408T-02-911024 / / 10/24/91 Talllnga Dry Cora 4 14-16 L-AP1B404T-MS-91 1024 J / 10/24/91 Talllnga Dry Core 4 14-16 L-AP1B400T-01-811024 / / 10/24/91 Talllnga Dry Cora 4 16.6-17 L-AP1B4078-01-B11024 / 10/24/91 Subaoll Split Spoon 4 19 20 L-AP1B408S-01-611024 / 10/24/91 Subaoll Dry Core 4 19-20 U-AP1B4088 01-911024 / / 10/24/91 Subaoll Dry Core 4 23.6-24 L-AP1B4103 01-81 1024 / / 10/24/91 Subaoll Dry Core 4 24-26 L-AP1B410S-01-S11024 J 10/24/91 Subaoll Dry Core 4 29-30 L-AP1B4128 01 911024 / / 10/24/91 Subaoll Dry Core 4 31.6-32 L-AP1B413S-01-911024 / 10/24/91 Subaoll Split Spoon 4 34-36 L-AP1B4148-01-911024 / / 10/24/91 Subaoll Dry Core 4 38-39 L-AP1B41B8-01-911024 / / 10/24/91 Subaoll Split Spoon APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST , . ————— 7 Q 0 8 N A Q E E P U R A O 0 E T C 1 T C C R H Q E H 1 1 1 C Data Matarial Simple Impoundment Boring f Dapth (ft) Sample * C E A E V Collacted Typ« Type H M T N E 1 T D O N Main 6 4-6 L-AP1B602T-01-91 1023 / 10/23/91 Tilling* Dry Cora 6 4-6 L-AP1B602T-01-91 1023 / / 10/23/91 Tailing* Dry Cora 6 2-3 L-AP1B602T-01-911023 / 10/23/91 Talllnga Dry Cora 6 46 L-AP1B602T-01-911023 / / 10/23/91 Tailing! Dry Cora 6 8-10 L-AP1 B603T-01 -9 1 1023 / / 10/23/91 Talllnga Dry Cora 6 10.7-12 L-AP1B604T-01-911023 / / 10/23/91 Talllnga Split Spoon e 14-16 L-AP1B606T 01-91 1023 / / 10/23/91 Tailing* Dry Cora 6 18-17 L-AP1B608S-01-911023 / / 10/23/91 Tailing* Split Spoon 6 18-19 L-AP1B607S 01-911023 / 10/23/91 Subaoll Dry Cora 6 19-20 L-AP1B607S 01-91 1023 / / 10/23/91 Subaoll Dry Cora E 19-20 L-AP1B6078-01-911023 / 10/23/91 Subtoll Dry Cora 6 19-20 L-AP1B6073 02-91 1023 / / 10/23/91 Subaoll Dry Cora 6 19-20 L- API B6078 MS-91 1023 / / 10/23/91 Subaoll Dry Cora 6 20.6-22 L-AP1B608S-01-91 1023 / / 10/23/91 Subaoll Split Spoon 6 24-26 L-AP1B609801-911023 / / 10/23/91 Subioll Dry Cora 6 26.6-27 L-AP1B6108-01-911023 J / 10/23/91 Subtoll Split Spoon 6 29-30 L-AP1B61 18 01-911023 / / 10/23/91 Subaoll Dry Cora 6 30.6-32 L-AP1B612S-01-911023 / / 10/23/91 Sufaaoll Split Spoon ______APACH E TAILINGS TEST HOLES - MASTER SAMPLE LIST______Q 0 s N A a E E p U R A O 0 E T C / T C C R H a E H 1 1 1 c D«to Material Sample Impoundment Boring 1 Dapth (It) Sample t C E A E V Collocted Typa Type H M T N E 1 T D O N Main 6 34-36 L-AP1B613S 01-911023 / / 10/23/91 Subaoil Dry Cora e 36.6-37 L-AP1B614S 01-911023 / / 10/23/81 Subaoll Split Spoon 6 36.6-37 L-AP1BE14S 01-91 1023 .. / 10/23/91 Subaoil Split Spoon 6 39-40 L-AP1B616S-01-B11023 / / 10/23/91 Subaoll Dry Cora 6 40.3-42 L-AP1B616S 01-911023 / / 10/23/91 Subaoil Split Spoon E 4O.3-42 L- API B61 65-01 -9 1 1 023 J 10/23/91 Sufaaoll Split Spoon Main 6 2.6-6 L-AP1B602T-01-811022 S 10/22/91 Tailing* Dry Cora 0 1.6-2.6 L- API B602T-01 -9 1 1 022 / 10/22/91 Talllngi Dry Cora a 2.6-6 L-AP1B002T-01-911022 / / 10/22/91 Talllnga Dry Core e 67 L-AP1B603T 01-91 1022 / / 10/22/91 Talllnga Split Spoon e 9- 1O L-AP1B604T-01-B1 1O22 / / 10/22/91 Talllnga Dry Core e 11-12 L-AP1B6O6T-01-91 1022 / / 10/22/91 Tallinoa Split Spoon a 14-16 L-AP1B806T-01-91 1022 / / 10/22/91 Talllnga Dry Core 6 18-17 L-AP1B807T-01-911022 / 10/22/91 Talllnga Split Spoon e 16-17 L-AP1B607T-02-911022 / / 10/22/91 Talllnga Split Spoon e 18-17 L- API B607T- MS-91 1022 / / 10/22/91 Talllnga Split Spoon 0 16-17 L-AP1BB07T-01-811022 / / 10/22/81 Talllnga Split Spoon 0 IB-IB L-AP1B608T 01-91 1022 / 10/22/91 Talllnga Dry Cora ______APACH E TAILINGTEST HOLS E ASTE RSA MPLE LIST ______=r=^^======:S-—M ., ••aaiaiaMM ; "... Q 0 s N A Q E E p U R A O 0 E T C / T C C R H Q E H 1 1 1 C Date Material Sample Impoundment Boring 1 Depth (ft) Sample * C E A E V Collected Typo Type H M T N E 1 T 0 0 N Main e 21-22 L-AP1B809S-01-911022 / / 10/22/91 Sutaaoll Split Spoon 8 24-26 L-AP1B010S-01-911022 / / 10/22/91 Subaoll Dry Core e 28-27 L-AP1B81 18-01-91 1022 / / 10/22/91 Subeoll Split Spoon 0 29-30 L-AP1B812S-01-811022 / / 10/22/91 Subaoll Dry Core e 31-32 L-AP1B613S 01-811022 / 10/22/91 Subaoll Split Spoon 6 31-32 L- API BO1 35-01 -9 11 022 / / 10/22/91 Subaoll Split Spoon a 34-36 L-AP1B814S01-911022 / / 10/22/91 Subaoll Dry Core e 38-37 L-AP1B616S-01-911022 J / 10/22/91 Subaoll Split Spoon a 39-40 L-AP1BOteS-01-911022 J / 10/22/91 Subaoll Dry Cora 6 41-42 L- API 681 78 01 -8 11 022 S / 10/22/91 Subaoll Split Spoon 6 41-42 L-AP1B817S-01-911022 J 10/22/91 Subaoll Split Spoon Main 7 0-6 L-AP1TMW701 8-01 -91 1009 / 10/9/91 Subaoll Cyclone 7 6-10 L-AP1TMW7028-01-B1 1009 / 10/9/91 Subaoll Cyclone 7 10-16 L-AP1TMW703S-01-91 1009 / 10/9/91 Subaoll Cyclone 7 16-20 L-AP1TMW704S-01-91 1009 / 10/9/91 Subaoll Cyclone 7 20-26 L- A PI TMW7063-01 -9 1 1 009 / 10/9/91 Subaoll Cyclone 7 26-30 L-AP1TMW7088-01-91 1009 / 10/9/91 Subaoll Cyclone 7 30-36 L-AP1TMW7078-01-91 1009 / 10/9/91 Subaoll Cyclone APACHE TAILINGS TEST HOLf ;s-w ASTE R SAMPLE LIST =— - — —— -- - *" .•• —— • -r— • ————— Q 0 s N A Q E E p U R A 0 O E T C I T C C R H a E H 1 1 1 c Dlta Material Sampla Impoundment Boring f Depth lit) Sample f C E A E V Collectod Typa Type H M T N E 1 T 0 O N Miln 7 36-40 L-AP1TMW7083-01-91 1008 / 10/9/81 Subioll Cyclona 7 40-46 I-AP1TMW709S-01-B1 1008 / 10/9/91 Subioll Cyclona 7 46-60 L-AP1TMW710S-01-91 1009 / 10/9/91 Subsoil Cyclono 7 60-66 L-AP1TMW711S 01-911009 / 10/9/91 Sutatoll Cyclone 7 66-60 L-AP1TMW712S 01-911009 / 10/9/91 Subioll Cyclono 7 60-66 L-AP1TMW7I3S-01-911009 / 10/9/91 Subtoll Cyclona 7 66-68 L-AP1TMW714S-01-91 1009 / 10/9/91 Subsoil Cyclone M.ln 8 0-10 L-AP1B8LST-01-911023 / 10/23/91 Talllngi Compodta 8 3.6-4 L-AP1B802T-01-911023 / 10/23/91 Tailing* Dry Cora a 3.6-4 L-AP1B802T-01-911023 / / 10/23/91 Tilling* Dry Cora a 3.6-4 L-AP1B802T-01-911023 / 10/23/91 Tailing* Dry Core 8 6-7 L-AP1B803T-01-911023 / 10/23/91 Tailing* Split Spoon a 6-7 L-AP1BB03T-01-911023 / / 10/23/91 Tailing* Split Spoon a 9-10 L-AP1BB04T-01-911023 / 10/23/91 Tailing* Dry Cora a 9-10 L-AP1B804T-01-911023 / / 10/23/91 Tailing* Dry Cora a 14-16 L-AP1B8068-01-91 1023 / 10/23/91 Tailing* Dry Cora a 14-16 L-AP1B806S 01-911023 / / 10/23/91 Tailing* Dry Cora a 16-17 L-AP1B8068-01-911023 / 10/23/91 Tailing* Split Spoon APACHE TAILINGS TEST HOLES • MASTER SAMPLE LIST Q 0 s N A Q E E p U R A O O E T C / T C C R H a E H 1 1 1 C D»te Material Sample Impoundment Boring f Depth (hi Sample t C E A E V Collected Type Type H M T N E 1 T D 0 N Main e 18-20 L-AP1B8078-01-B11023 / 10/23/91 Tailing* Dry Core 8 19-20 L-AP1B807S-01-811023 / / 10/23/91 Tailing! Dry Core 8 24-26 L-AP1B808S-01-811023 / 10/23/81 Tailings Dry Core 8 24-26 U-AP1B808S 01-911023 / / 10/23/81 Tailing* Dry Core 8 28-30 L-AP1B809S 01-911023 S 10/23/01 Tailing! Dry Core a 28-30 L-AP1B8OBS 01-911023 / / 10/23/81 Tilling! Dry Cor* 8 31-32 L-AP1B810S 01-911023 / 10/23/81 ___ Tailing* Spill Spoon 8 34-36 L-AP1B811S 01-911023 / 10/23/81 Tailing* Dry Core 8 34-35 L-AP1B81 18 01-811023 / / 10/23/81 Tilling! Dry Core 8 39-40 L-AP1 88128-01-911023 / 10/23/81 Tailing* Dry Core 8 38-40 L-AP1B812S 01-911023 / ^ 10/23/91 Tailing! Dry Cor* 8 44-46 L-AP1B613S 01-811023 / 10/23/91 Tailing* Dry Core 8 44-46 L-AP1B81 33-01-81 1023 / / 10/23/81 Tailing* Dry Cor* 8 46.7-47 L-AP1B814S-01-911023 / 10/23/81 Tailing* Split Spoon 8 46.7-47 L-AP1B814S-01-811023 / / 10/23/81 Tilling* Split Spoon 8 49-60 L- API B81 68-01 -9 11 023 ^ ^ 10/23/91 Subcoll Split Spoon 8 49-60 L-AP1B816S-01-911023 / 10/23/91 Subioll Split Spoon 8 64-60 L-AP18818S 01-911023 / 10/23/91 Subioll Split Spoon APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST 0 Q s N A Q E E p U R A 0 O E T C / T C C n H Q E H 1 i 1 C Data Malarial Simpla Impoundment Boring * Depth Ift) Simpla * C E A E V Collected Type Type H M T N E 1 T D O N Main 8 54-66 L- API 681 88 01-811023 / / 10723/91 Sub.oll Split Spoon 8 69-61 L-AP1 881 73-01-81 1023 / 10/23/91 Subioll Split Spoon 8 69-61 L-AP1B81 73 01-911023 / / 10/23/91 Sub.oll Split Spoon 8 63-63.3 L-AP1B818S 01-911023 / / 10/23/91 Subtoll Split Spoon Main 9 3-4 L-AP1B902T-01-911021 / 10/21/91 Tallinga Dry Cora e 3-4 L-AP1B902T-01-911021 / / 10/21/91 Tilling! Dry Cor* a 9-10 L-AP1B903T-01-911021 / / 10/21/91 Tilling* Dry Cora e 11-12 L-AP1B904T-01-911021 / / 10/21/91 Tilling* Split Spoon 9 14-16 L-AP1B906T-01-911021 / / 10/21/91 Tilling! Dry Core 8 14-16 L-AP1B906T-01-91 1021 / 10/21/91 Tilling* Dry Cora 0 14-16 L-AP1B906T-02-911021 / / 10/21/91 Tilling* Dry Cora 9 14-16 L- API B906T- MS-91 1021 / J 10/21/91 Tilling* Dry Cora 9 27.3-24 L-AP1TMW906T-91 1021 / 10/21/91 Tilling* Shalby Tuba 9 18.6-19.6 L-AP1 89078-01-91 1021 S 10/21/91 Subtoll Spirt Spoon 9 18.6-19.6 L-AP1 89078-01 -9 11 021 / / 10/21/91 8ub*oH Split Spoon 9 23.7-24 L-AP1B808T-01-811021 / 10/21/91 Tilling* Dry Cora 9 24-26 L-AP1i80BS-01-911021 / / 10/21/91 Subcoll Dry Cor* 9 29-30 (.•API B909S-01-91 1021 / / 10/21/91 Bubioll Dry Cora APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST Q d s N A Q E E p U R A 0 0 E T C / T C C n H Q E H 1 t 1 C Date Matarial Sampla . Impoundment Boring f Dapth (ft) Sampla * C E A E V Collected Typa Type H M T N E 1 T D O N Main a 31-32 L- API 89) OS-01 -9 11 021 / / 10/21/91 Subaoll Dry Core 9 31-32 L-AP1B910S 01-91 1021 / 10/21/91 Subsoil Dry Cora 9 32-34 L-AP1B91 18-01-91 1021 v' / 10/21/91 Subaoll Split Spoon 9 32-34 L-AP1B911S-01-911021 ^ 10/21/91 Subaoil Split Spoon Main 10 4-6 L-AP1B1002T-01-911022 J J 10/22/91 Tailing* Dry Cora 10 4-6 L-AP1B1O02T-01-91 1022 S 10/22/91 T«lllngi Dry Core 10 3-4 L-AP1B1002T-01-91 1022 J 10/22/91 Talllnga Dry Core 10 8-9 L-AP1B1003S 01-91 1022 / 10/22/81 Subaoll Dry Core 10 9-10 L-AP1B1 0033-01 -9 11 022 S / 10/22/91 Subaoll Dry Core 10 8.4-10 L-AP1B1O04S-01-811022 / / 10/22/91 Bubaoll Spilt Spoon 10 12.4-14 L-AP1B10068-01-91 1022 / 10/22/91 Subaoll Split Spoon 10 12.4-14 L-AP1B1006S-02-911022 / / 10/22/91 Subaoll Split Spoon 10 12.4-14 L-AP1B1006S-MS-911022 / / 10/22/91 Subaoll Split Spoon 10 12.4-14 L-AP1B1O06S-01-91 1022 / / 10/22/91 Subaoll Split Spoon 10 14-16 L-AP1B1006S-01-91 1022 / / 10/22/91 Subaoll Dry Cora 10 16.4-17 L-AP1B1007S-01-91 1022 / / 10/22/91 Subaoll Split Spoon 10 19-20 L- A PI B1 0088-01 -9 11 022 / / 10/22/91 Subaoll Dry Core 10 19-20 L-AP1B10088-01-911022 / 10/22/91 Subaoll Dry Core APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST Q Q S N A Q E E P U R A O O E T C / T C C R H a E H 1 1 1 c Date Material Sample Impoundment Boring 1 Depth (ft) Sample 1 C E A E V Collected Type Type H M T N E 1 T D O N Main 10 20.4-20.6 L-AP1B1009S-01-911022 / 10/22/91 Subaoll Split Spoon 10 20.6-22 L-AP1B10093-01-91 1022 / J 10/22/91 Subioll Split Spoon 10 23-24 L-AP1B101 OS-01-91 1022 / 10/22/91 Subtoll Dry Cor* 10 24-26 L- API B1 01 OS-01 -91 1O22 / 10/22/91 Subaoll Dry Cora 10 24-26 L-AP1 B1 01 OS-01 -91 1 022 / / 10/22/91 Subaoll Dry Cor* 10 25.4-26.6 L-AP1B101 1S-01-B1 1022 / / 10/22/91 Subaoll Split Spoon 10 26.6-27 L-AP1B101 26-01-91 1022 / / 10/22/91 Subaoll Split Spoon Main 11 16-17.2 L-AP1B1101T-01-911024 / 10/24/91 Talllnga Shalby Tube 11 20-66.6 L-AP1 B1 1 02T-01 -91 1 024 / 10/24/91 Talllnge Shelby Tube Number 2 1 0-2 L-AP2NCT-01-911029 / 10/29/91 Talllnga Compoalte 1 0-2 L-AP2NCT-01-911029 / / 10/29/91 Talllnga Compoarta 1 4-6 L-AP2B102T-01-911029 / 10/29/91 Talllnga Dry Core 1 4-6 L-AP2B102T02-911029 / / 10/29/91 Talllnga Dry Core 1 4-6 L-AP2B102T-MS-911029 / j 10/29/91 Talllnga Dry Core 1 4-6 L-AP2B102T-01-911029 / / 10/29/91 Talllnga Dry Core 1 6.6-9.8 L-AP2B103T-01-911029 / 10/29/91 Talllnga Dry Core 1 6.8-8.8 U-AP2B103T-01-911029 / / 10/29/91 Talllnga Dry Core 1 11-12 L-AP2B1 048-01-91 1029 / 10/29/91 Subaoll Bpltt Spoon APACHE TAILINGS TEST HOLES - MASTER SAMPLE LIST 0 0 S N A Q E E P U R A o O E T C / T C C R H Q E H 1 1 C Date Materiel Sample Impoundment Boring f Depth (It) Sample 1 C E A E V Collected Type Type H M T N E 1 T 0 O N Number 2 1 11-12 L-AP2B104S 01-911029 / / 10/29/91 Subeoll Split Spoon Number 3 1 0-2 L-AP3NCT-01 -911029 / / 10/29/91 Talllnge Compoelte 1 0-2 L-AP3NCT-01-911029 / 10/28/91 Tailings Compoelte 1 0-2 L-AP3NCT-02-911029 S / 10/29/91 Talllnge Compoeite 1 0-2 L-AP3NCT-MS 91 1029 S / 10/29/91 Talllnge Compoelte 1 4-6 L-AP3B1O2T-01-B11029 / y 10/29/01 Talllnge Dry Core 1 4-6 L-AP3B102T-01-9D029 ^ 10/29/91 Talllnge Dry Cora 1 6-7 L-AP3B1 033-0 1-8 11 029 / / 10/28/81 Subeoll Split Spoon t 6-7 L-AP3S1 038-01 -01 1028 / 10/28/81 SubeoU Split Spoon APPENDIX C TAILINGS GEOCHEMISTRY GEOCHEMICAL SAMPLES COLLECTED AND SUBMITTED Impoundment Test Hole Depth Sample Sample ID Sample Sample Type Analysis Parameters # (ft) Date Description Main 10/21/91 L-AP1W-03-911021 Water Equipment Rinsate Total Analytes 10/21/91 L-AP1W-04-911021 Water Trip Blank Total Analytes 10/24/91 L-AP1W-03-911024 Water Equipment Rinsate Total Analytes 10/24/91 L-AP1W-04-911024 Water Trip Blank Total Analytes 09/17/91 L-AP1W-04-910917 Water Trip Blank Total Analytes 09/22/91 L-AP1W-03-911022 Water Equipment Rinsate Total Analytes 09/22/91 L-AP1W-04-911022 Water Trip Blank Total Analytes 09/24/91 L-AP1W-04-9 10924 Water Trip Blank Total Analytes Downgrd. 1 11-12 09/24/91 L-AP1B101S-01-910924 Subsoil Split Spoon Total Analytes 1 16-17 09/24/91 L-AP1B102S-01-910924 Subsoil Split Spoon Total Analytes i . iigrd. 2 5-7 09/17/91 L-AP1B202S-01-910917 Subsoil Split Spoon Risk Assessment Metals 2 5-7 09/17/91 L-AP1B202S-02-910917 Subsoil Duplicate Risk Assessment Metals 2 5-7 09/17/91 L-AP1B202S-MS-910917 Subsoil Matrix Spike Risk Assessment Metals Downgrd. 3 4.8-6 09/17/91 L-AP1B302S-01-910917 Subsoil Split Spoon Total Analytes Main 4 3.7-5 10/24/91 L-AP1B402T-01-91 1024 Tailings Dry Core Total Analytes 4 9-10 10/24/91 L-AP1B404T-01-911024 Tailings Dry Core Risk Assessment Metals 4 14-15 10/24/91 L-AP1B406T-01-911024 Tailings Dry Core Total Analytes 4 14-15 10/24/91 L-AP1 B406T-02-91 1024 Tailings Duplicate Total Analytes 4 14-15 10/24/91 L-AP1B406T-MS-911024 Tailings Matrix Spike Total Analytes 4 19-20 10/24/91 L-AP1B408S-01-911024 Subsoil Dry Core Total Analytes GEOCHEMICAL SAMPLES COLLECTED / ^ND SUBMITTEI 3 ===== ^^^••••••••••••••••^MH = ~= Impoundment Test Hole Depth Sample Sample ID Sample Sample Type Analysis Parameters » (ft) Date Description Main 5 4-5 10/23/91 L-AP1B502T-01-911023 Tailings Dry Core Total Analytes 5 19-20 10/23/91 L-AP1B507S-01-911023 Subsoil Dry Core Total Analytes 5 19-20 10/23/91 L-AP1B507S-02-911023 Subsoil Duplicate Total Analytes 5 19-20 10/23/91 L-AP1B507S-MS-911023 Subsoil Matrix Spike Total Analytes 5 35.5-37 10/23/91 L-AP1B514S-01-911023 Subsoil Split Spoon Risk Assessment Metals 5 40.3-42 10/23/91 L-AP1B516S-01-911023 Subsoil Split Spoon Total Analytes Main 6 2.6-5 10/22/91 L-AP1B602T-01-911022 Tailings Dry Core Total Analytes 6 16-17 10/22/91 L-AP1B607T-01-911022 Tailings Split Spoon Risk Assessment Metals 6 16-17 10/22/91 L-AP1B607T-02-911022 Tailings Duplicate Risk Assessment Metals 6 16-17 10/22/91 L-AP1B607T-MS-911022 Tailings Matrix Spike Risk Assessment Metals 6 31-32 10/22/91 L-AP1B613S-01-911022 Subsoil Split Spoon Total Analytes 6 41-42 10/22/91 L-AP1B617S-01-911022 Subsoil Split Spoon Total Analytes Main 8 3.5-4 10/23/91 L-AP1B802T-01-911023 Tailings Dry Core Total Analytes 8 5-7 10/23/91 L-AP1B803T-01-911023 Tailings Split Spoon Risk Assessment Metals 8 9-10 10/23/91 L-AP1B804T-01-911023 Tailings Dry Core Total Analytes 8 14-15 10/23/91 L-AP1B805S-01-911023 Tailings Dry Core Total Analytes 8 19-20 10/23/91 L-AP1B807S-01-911023 Tailings Dry Core Total Analytes 8 24-25 10/23/91 L-AP1B808S-01-911023 Tailings Dry Core Total Analytes 8 29-30 10/23/91 L-AP1B809S-01-911023 Tailings Dry Core Risk Assessment Metals 8 34-35 10/23/91 L-AP1B811S-01-911023 Tailings Dry Core Total Analytes GEOCHEMICAL SAMPLES COLLECTED AND SUBMITTED Impoundment Test Hole Depth Sample Sample ID Sample Sample Type Analysis Parameters i (ft) Date Description Main 8 39-40 10/23/91 L-AP1B812S-01-911023 Tailings Dry Core Total Analytes 8 44-45 10/23/91 L-AP1B813S-01-911023 Tailings Dry Core Risk Assessment Metals 8 46.7-47 10/23/91 L-AP1B814S-01-911023 Tailings Split Spoon Total Analytes 8 49-50 10/23/91 L-AP1B815S-01-911023 Tailings Split Spoon Total Analytes 8 54-56 10/23/91 L-AP1B816S-01-911023 Tailings Split Spoon Total Analytes 8 59-61 10/23/91 L-AP1B817S-01-911023 Tailings Split Spoon Total Analytes Main 9 14-15 10/21/91 L-AP1B905T-01-911021 Tailings Dry Core Total Analytes 9 14-15 10/21/91 L-AP1B905T-02-911021 Tailings Duplicate Total Analytes 9 14-15 10/21/91 L-AP1B905T-MS-91 1021 Tailings Matrix Spike Total Analytes 9 18.5-19.5 10/21/91 L-AP1B907S-01-911021 Subsoil Split Spoon Total Analytes 9 31-32 10/21/91 L-AP1B910S-01-911021 Subsoil Dry Core Risk Assessment Metals 9 32-34 10/21/91 L-AP1B911S-01-911021 Subsoil Split Spoon Total Analytes Main 10 4-5 10/22/91 L- AP1 B 1 002T-0 1-911022 Tailings Dry Core Total Analytes 10 12.4-14 10/22/91 L-AP1B1005S-01-911022 Subsoil Split Spoon Risk Assessment Metals 10 12.4-14 10/22/91 L-AP1B1005S-02-911022 Subsoil Duplicate Risk Assessment Metals 10 12.4-14 10/22/91 L-AP1B1005S-MS-911022 Subsoil Matrix Spike Risk Assessment Metals 10 19-20 10/22/91 L-AP1B1008S-01-911022 Subsoil Dry Core Total Analytes 10 24-25 10/22/91 L-AP1B1010S-01-911022 Subsoil Dry Core Total Analytes Number 2 1 4-5 10/29/91 L-AP2B102T-01-911029 Tailings Dry Core Total Analytes 1 4-5 10/29/91 L-AP2B102T-02-911029 Tailings Duplicate Total Analytes GEOCHEMICAL SAMPLES COLLECTED AND SUBMITTED Impoundment Test Hole Depth Sample Sample ID Sample Sample Type Analysis Parameters * (ft) Date Description Number 2 1 4-5 10/29/91 L-AP2B102T-MS-91 1029 Tailings Matrix Spike Total Analytes 1 8.8-9.8 10/29/91 L-AP2B103T-01-911029 Tailings Dry Core Total Analytes 1 11-12 10/29/91 L-AP2B104S-01-911029 Subsoil Split Spoon Total Analytes Number 3 1 4-5 10/29/91 L-AP3B102T-01-911029 Tailings Dry Core Total Analytes 1 5-7 10/29/91 L-AP3B103S-01-911029 Subsoil Split Spoon Total Analytes NUTRIENT SAMPLES COLLECTED Impoundment Sample Sample ID Sample Sample Type Date Description Main 10/21/91 L-AP1NCT-01-911021 Tailings Composite 10/21/91 L-AP1NCT-02-911021 Tailings Duplicate 10/21/91 L-AP1NCT-MS-911021 Tailings Matrix Spike Number 2 10/29/91 L-AP2NCT-01-911029 Tailings Composite Number 3 10/29/91 L-AP3NCT-01-911029 Tailings Composite 10/29/91 L-AP3NCT-02-911029 Tailings Duplicate 10/29/91 L-AP3NCT-MS-911029 Tailings Matrix Spike SURFACE TAILINGS SAMPLING DATA SUMMARY Sample ID Sample Sample Sample Sample Description Analysis Parameters Date Time Type L-AP1T01-01-910919 09/19/91 1550 Composite Crusted Tailings Risk Assessment Metals L-AP1T02-01-910919 09/19/91 1547 Composite Loose Below Crust Risk Assessment Metals L-AP1T03-01-910919 09/19/91 1700 Composite Embankment Face Risk Assessment Metals QA\QC Samples L-MA1T-02-910919 09/19/91 1045 Composite Duplicate Risk Assessment Metals L-MA1T-MS-910919 09/19/91 1045 Composite Matrix Spike Risk Assessment Metals L-MA1T-03-910919 09/19/91 1010 Water Field Blank Risk Assessment Metals L-MA1T-04-910919 09/19/91 1100 Water Equipment Rinsate Risk Assessment Metals APPENDIX D GROUNDWATER 1 MONITOR ING WELL DEVELOPMENT DATA SUMMARY q^**ifmfi^*SSlSSS*lfiiilf^ • " •- - Monitoring Development Development Initial Water Casing Well ID Date Method Level From Volume Volumes Purging Estimated Specific 1 1 Top of PVC Purged Purged Time Production PH1 Conductivity Temperature (ft) (gal) (min) (gpm) (std units) (/ymhos/cm) (°C) AP1TMW1 10/9/91 4" Pump 12.38 88.8 10.4 89.0 1.0 5.68 2.926 11.6 AP1TMW2 10/4/91 4" Pump 3.34 85.8 10.3 292.0 0.3 6.72 908 9.2 AP1TMW3 10/7-8/91 4" Pump 2.47 151.8 11.4 210.0 0.7 5.87 1,520 10.5 AP1TMW7 10/16/91 4" Pump 62.96 140.2 14.8 39.0 3.6 7.26 439 5.9 AP1TMW8 11/21/91 N/A Dry N/A N/A N/A N/A N/A N/A N/A AP1TMW9 11/21-26/91 Disposable 19.41 16.5 10.6 66 min over « 0.01 6.29 6.720 6.5 Bailer 4 days AP1TMW10 11/21/91 N/A Dry N/A N/A N/A N/A N/A N/A N/A AP2TMW1 11/21/91 N/A Dry N/A N/A N/A N/A N/A N/A N/A 'The reported pH, specific conductivity and temperature values were measured at the conclusion of well development. MONITORING WELL SAMPLING DATA SUMMARY Monitoring Sample Sampling Initial Water Casing Well ID Date Method Level From Volume Volumes Specific 1 1 Top of PVC Purged Purged PH1 Conductivity Temperature (ft) (gal) (std units) (/ymhos/cm) (°C) AP1TMW1 11/21/91 2" Grundfos 11.94 28 3.0 5.50 1,720 8.4 AP1TMW2 11/21/91 2" Grundfos 2.69 27 3.0 6.49 827 7.0 AP1TMW3 11/21/91 2" Grundfos 2.56 40 2.4 7.07 523 8.0 AP1TMW7 11/22/91 2" Grundfos 61.98 34 3.4 7.27 441 4.3 AP1TMW8 11/21/91 N/A Dry N/A N/A N/A N/A N/A AP1TMW9 11/27/91 Disposable 19.05 6 1.9 6.15 6,580 7.4 Bailer AP1TMW10 11/21/91 N/A Dry N/A N/A N/A N/A N/A AP2TMW1 11/21/91 N/A Dry N/A N/A N/A N/A N/A 'The reported pH, specific conductivity and temperature were measured at the time of sample collection. GROUNDWATER QUALITY SAMPLES COLLECTED Monitoring Sample ID Sample Sample Type of Sample Well ID Date Time CZ1TMW6 L-CZ1TMW06-03-91 1116 11/16/91 1840 Field Blank L-CZ1 TM W06-04-9 11116 11/16/91 1800 Equipment Rinsate AP1TMW1 L-AP1TMW01-01-911121 11/21/91 1215 Primary L-AP1TMW01-02-911121 11/21/91 1215 Duplicate L-AP1TMW01 -MS-91 1 1 21 11/21/91 1215 Matrix Spike AP1TMW2 L-AP1TMW02-01-911121 11/21/91 1715 Primary AP1TMW3 L-AP1TMW03-01-911121 11/21/91 1430 Primary L-AP1TMW03-04-911121 11/21/91 1500 Equipment Rinsate AP1TMW7 L-AP1TMW07-01-911122 11/22/91 1000 Primary L-AP1TMW07-02-91 1 1 22 11/22/91 1000 Duplicate L-AP1TMW07-MS-91 1 1 22 11/22/91 1000 Matrix Spike AP1TMW8 N/A N/A N/A N/A AP1TMW9 L-AP1TMW09-01-91 1 127 11/27/91 1330 Primary L-AP1TMW09-02-91 1 127 11/27/91 1330 Duplicate L-AP1TMW09-MS-91 1 127 11/27/91 1330 Matrix Spike L-AP1TMW09-03-91 1 127 11/27/91 1230 Field Blank AP1TMW10 N/A N/A N/A N/A AP2TMW1 N/A N/A N/A N/A MONITORING WELL WATER LEVEL SUMMARY Monitoring Measurement Measurement Depth to Water Groundwater Well ID Date Time (ft) Elevation (ft) AP1TMW1 10/09/91 1049 12.38 10031.78 10/18/91 1631 12.40 10031.76 11/21/91 1125 11.94 10032.22 01/17/92 1245 12.27 10031.89 02/18/92 1710 12.05 10032.11 03/1 6/92 1433 12.03 10032.13 04/13/92 0904 1 1 .72 10032.44 05/18/92 1130 11.56 10032.60 06/1 5/92 1457 11.61 10032.55 07/20/92 1642 11.44 10032.72 08/17/92 1714 11.93 10032.23 09/21/92 1555 12.19 10031.97 10/26/92 1236 12.55 10031.61 AP1TMW2 10/04/91 1205 3.34 10037.80 10/05/91 0855 3.22 10037.92 11/21/91 1630 2.69 10038.45 01/15/92 1600 FROZEN FROZEN 02/18/92 1725 FROZEN FROZEN 03/16/92 1403 FROZEN FROZEN 04/13/92 0857 FROZEN FROZEN 05/18/92 1140 3.21 10037.93 06/15/92 1430 3.23 10037.91 07/20/92 1624 2.84 10038.30 08/1 7/92 1739 2.89 10038.25 09/21/92 1542 3.50 10037.64 10/26/92 1229 3.39 10037.75 MONITORING WELL WATER LEVEL SUMMARY Monitoring Measurement Measurement Depth to Water Groundwater Well ID Date Time (ft) Elevation

Monitoring Date Initial Water Screened1 Type of Hydraulic Cond. Hydraulic Cond. Hydraulic Well ID Level' Interval Slug Test Bouwer & 2 Rice Bouwer &2 Rice Cond. (ft) (ft) (Partially) (Fully) Hvorslev (cm/sec) (cm/sec) (cm/sec) AP1TMW1 01/17/92 12.27 15.0- 25.0 Falling Head 3.5x1 0'3 4.5x1 03 7.7x103 AP1TMW1 01/17/92 12.27 15.0 - 25.0 Recovery 3.0x103 3.0x103 7.0x1 03 AP1TMW2 01/15/92 2.3 Frozen 11.0-16.0 N/A N/A N/A N/A AP1TMW3 01/15/92 2.72 15.0-25.0 Falling Head 1.5x10" 2.0x10" 3.0x10" AP1TMW3 01/15/92 2.72 15.0-25.0 Recovery 1.3x10'" 1.7x10" 2.8x10^ AP1TMW7 01/17/92 61.83 64.45 - 74.45 Falling Head 3.8x10'* 4.8x102 9.4x1 0'2 AP1TMW7 01/17/92 61.83 64.45 - 74.45 Recovery 4.7x1 02 6.0x1 0'2 l.lxlO"1 AP1TMW7 01/21/92 61.85 64.45 - 74.45 Falling Head 8.5x1 0'2 1.1x10' 1.7x10' AP1TMW7 01/21/92 61.85 64.45 - 74.45 Recovery 1.2X10'1 1.5x10'' 1.7x10' AP1TMW8 01/17/92 Dry 22.5 - 37.5 N/A N/A N/A N/A AP1TMW9 01/15/92 20.04 11.3-21.3 Recovery 7.2x1 0'6 N/A 5.9x106 (bail down) AP1TMW10 01/17/92 Dry 11.5 - 21.5 N/A N/A N/A N/A AP2TMW1 01/15/92 Dry 6.0- 9.1 N/A N/A N/A N/A 'Water levels and screened intervals measured from the top of PVC casing. 'Partially refers to the screen partially penetrates the saturated zone, while Fully refers to the screen fully penetrates the saturated zone. Apache Monitor Well AP1TMW1 Falling Head DATA SET: «p100.Inp ' *J- H 1 I i I J I I I I I I I I I I I I I I I 1 I I I I I I t | I i I I I I t 1 I | II I I I I I H AQUIFER TYPE: Uneonfintd SOLUTION METHOD: Bouwtr -fllet ESTIMATED PARAMETERS: C i 0.00691 ft/mm yO • 1.1S1 fl C V TEST DATA: E MO » 1.47 ft O.ICS7 (t » 150. ft H » 12.73 ft

I I I II I I I I I I I I IAI I I l/kl I 0.01 0. 1. 2. 3. 4. 5. Time (min)

STATISTICAL HATCH PARAMETER ESTIMATES; WEIGHTED RESIDUAL STATISTICS: Estimate Std. Error Number of residuals...... , 39 K = 6.9098E-003 +/- 3.1752E-005 Number of estimated parameters. , Z yO = 1.8509E+000 +/- 5.2147E-003 Degrees of freedom...... , 37 Residual mean...... 0.001497 ANALYSIS OF MCOEl RESIDUALS; Residual standard deviation.... 0.006476 residual = calculated - observed Residual variance...... 4.193E-005 weighted residual = residual * weight MODEL RESIDUALS; Time Observed Calculated Residual Weight 0.0833 .47 1.4786 -0.0086114 0.1 .41 1.4135 -0.0035126 0.1166 .35 1.3516 -0.0016443 0.1333 .29 1.2921 -0.0021355 0.15 .24 1.2352 0.0047532 0.1666 .18 1.1812 -0.001181 0.1833 .13 1.1292 0.00082279 0.2 1.08 1.0795 0.00053702 0.2166 1.04 1.0322 0.0077842 0.2333 0.99 0.98677 0.0032295 0.25 0.95 0.94333 0.006674 0.2666 0.9 0.90204 -0.0020374 0.2833 0.87 0.86232 0.0076766 0.3 0.83 0.82436 0.0056421 0.3166 0.78 0.78828 •0.0082764 0.3333 0.76 0.75357 0.006429 0.4167 0.6 0.60182 -0.001824 0.5 0.48 0.48076 -0.000764 0.5833 0.38 0.38406 -0.0040558 0.6667 0.3 0.30672 -0.0067183 0.75 0.24 0.24502 -0.0050203 0.8333 0.19 0.19573 -0.0057332 0.9167 0.15 0.15632 -O.Q063183 1 0.12 0.12487 -0.0048741 Apache Monitor Uell AP1TMU1 Falling Head (cont.) HOOEL RESIDUALS (eont.); Time Observed Calculated Residual Weight 1.0833 0.09 0.099755 -0.009755 1 1.1667 0.08 0.079667 0.00033272 1.25 0.07 0.063642 0.0063582 1.3333 0.05 0.05084 -0.00083992 1.4166 0.04 0.040613 -0.0006132 1.5 0.04 0.032435 0.0075651 1.5833 0.04 0.02591 0.01409 1.6667 0.03 0.020693 0.0093072 1.75 0.02 0.01653 0.0034696 1.8333 0.02 0.013205 0.0067948 1.9167 0.02 0.010546 0.0094539 2 0.01 0.0084247 0.0015753 1 3.5 0.01 0.00014763 0.0098524 1 4 0.01 3.8345E-005 0.0099617 1 4.5 0.01 9.9599E-006 0.00999 1 Head Ratio, h/ho (ft/ft) pb I___I J_I

tpo_

p_

51

PCO. H 3 g_ a 5" Da. ^ a> ro n l/l

o> o q? Apache Monitor Well AP1TMW1 Recovery DATA SET: AP10 t. IMP 10. pr 02112/92 AQUIFER TYPE: Unconf i n«<3 SOLUTION METHOD: 9ouw4r-flIc* ESTIMATED PARAMETERS: C > 0-005983 rtlmin >0 . 1.9 ft TEST DATA: HO * 1.74 ft re = 0.1667 rt o rw « 0.5 ft _o L • 'to. ft ft > 130. ft I H > 12.73 ft

0.01 0. 1. 2. 3. Time (min)

STATISTICAL HATCH PARAMETER ESTIMATES: WEIGHTED RESIDUAL STATISTICS; Estimate Std. Error Number of residuals...... 39 K = 5.9878E-003 +/- 6.0564E-005 Number of estimated parameters. . 2 yO = 1.8999E+000 +/- 1.00S8E-002 Degrees of freedom...... 37 Residual mean...... 0.005301 ANALYSIS OF MODEL RESIDUALS: Residual standard deviation..... 0.01737 residual = calculated - observed Residual variance...... 0.0003016 weighted residual = residual * weight MODEL RESIDUALS: Time Observed Calculated Residual Weight 0.05 1.74 1.6904 0.049597 0.0666 1.66 1.6261 0.033902 0.0833 1.58 1.5639 0.016127 0.1 1.5 1.504 -0.0040295 1166 1.44 1.4468 -0.0068139 1333 1.38 1.3914 •0.01145 0.15 1.32 1.3382 -0.018204 1666 1.27 1.2873 -0.017297 1833 1.23 1.238 -0.0080369 0.2 1.18 1.1907 -0.010662 0.2166 1.14 1.1454 -0.0053674 0.2333 1.09 1.1015 -0.011538 0.25 1.05 1.0594 -0.0093867 0.2666 1 1.0191 -0.019086 0.2833 0.97 0.98009 -0.010089 0.3 0.93 0.94259 -0.012585 0.3166 0.9 0.90673 -0.0067278 0.3333 0.86 0.87203 -0.012031 0.4167 0.71 0.71764 -0.0076416 0.5 0.59 0.59072 -0.00072432 0.5833 0.49 0.48625 0.0037472 0.6667 0.41 0.40016 0.0098361 0.75 0.33 0.32939 0.00060639 Apache Monitor Well AP1TMU1 Recovery (coot.) HOOEL RESIDUALS (cont.); Time Observed Calculated Residual Weight 0.8333 0.29 0.27114 0.018861 0.9167 0.24 0.22314 0.016865 1 0.2 0.18367 0.016327 1.0833 0.16 0.15119 0.0088101 1.1667 0.13 0.12442 0.0055776 1.25 0.12 0.10242 0.017582 1.3333 0.11 0.084305 0.025695 1.4166 0.09 0.069395 0.020605 1 1.5 0.08 0.057109 0.022891 1 1.5833 0.07 0.047009 0.022991 1 1.6667 0.06 0.038686 0.021314 1 1.75 0.05 0.031845 0.018155 1 1.8333 0.05 0.026213 0.023787 1 1.9167 0.03 0.021572 0.008428 1 2 0.03 0.017757 0.012243 1 2.5 0.01 0.0055211 0.0044789 1 Apache Monitor Well AP1TMW3 Falling Head DATA SET: p : ap300.Inp ' U • -i M 1 1 I I I I I 1 I i ] 03/12/92 AQUIFER TYPE: Unconf ln« ISO. ft : 0.1 H . 22.28 ft

I I I [ I I I I I I I I I I I I I I I I I I I I I I I I I I I ! I IAl ) I I 0.01 0. 10. 20. 30. 40. Time (min)

Ov... PARAMETER ESTIMATES; WEIGHTED RESIDUAL STATISTICS: :imate Std. Error Number of residuals...... 67 4E-004 +/• 2.0224E-006 Number of estimated parameters. . 2 .7E+000 +/- 4.5010E-003 Degrees of freedom...... 65 Residual mean...... -0.001442 RESIDUALS: Residual standard deviation.... 0.01927 ulated - observed Residual variance...... 0.0003713 ial = residual * weight MODEL RESIDUALS: Time Observed Calculated Residual Weight 0.2333 1.92 1.8605 0.05954 1 0.25 .89 1.8572 0.03281 1 0.2666 .88 1.8539 0.026054 1 0.2833 .87 1.8507 0.019312 1 0.3 .86 1.8474 0.012564 1 0.3166 .86 1.8442 0.015791 1 0.3333 .85 1.841 0.0090313 1 0.4167 1.84 1 .8249 0.01513 1 0.5 1.81 1.8089 0.0010698 1 0.5833 1.79 1.7931 -0.0031301 1 0.6667 1.78 1.7774 0.0025507 1 0.75 1.75 1.7619 -0.011924 1 0.8333 1.74 1.7465 -0.0065347 1 0.9167 1.73 1.7313 -0.0012614 1 1 1.71 1.7161 -0.0061397 1 1.0833 1.69 1.7012 -0.01115 1 1.1667 1.67 1.6863 -0.016274 1 1.25 1.66 1.6715 -0.011545 1 1.3333 1.64 1.6569 -0.016945 1 1.4166 1.63 1.6425 -0.012472 1 1.5 1.61 1 .6281 -0.018109 1 1.5833 1.6 1.6139 -0.013888 1 1.6667 1.58 1.5998 -0.019775 1 Apache Monitor Well AP1TMW7 Falling Hd1 DATA SET: P:AP700.INP 1. an 14/92 AQUIFER TYPE: Uncon fIn«d SOLUTION METHOD: 8ouw«r-Diet ESTIMATED PARAMETERS: C - 0.01524 ftlfflln >0 > 0.5474 ft Vc TEST DATA: £4) 0.1 MO • 0.23 rt

i i i i 0.01 0. 0.05 0.1 0.15 0.2 Time (min)

STATISTICAL HATCH PARAMETER ESTIMATES: WEIGHTED RESIDUAL STATISTICS; Number of residuals...... 13 Estimate Std. Error Number of estimated parameters. , 2 K = 7.5244E-002 +/- 5.1409E-003 Degrees of freedom...... , 11 yO = 5.4742E-001 +/- 4.5690E-002 Residual mean...... 0.004111 Residual standard deviation.... 0.00854 Residual variance...... 7.293E-005 AHALYSIS OF MODEL RESIDUALS: residual = calculated - observed weighted residual = residual * weight HOOEL RESIDUALS: Time Observed Calculated Residual Weight 0.0333 0.23 0.22841 0.0015897 1 0.05 0.15 0.14735 0.002652 1 0.0666 0.09 0.095304 •0.0053043 1 0.0833 0.05 0.061481 -0.011481 1 0.1166 0.04 0.025653 0.014347 1 0.15 0.01 0.010676 -0.00067566 1 0.1666 0.01 0.006905 0.003095 1 0.1833 0.01 0.0044544 0.0055456 1 0.2 0.01 0.0028736 0.0071264 1 0.2166 0.01 0.0018586 0.0081414 1 0.25 0.01 0.00077347 0.0092265 1 0.2666 0.01 0.00050028 0.0094997 1 0.2833 0.01 0.00032273 0.0096773 1 Head Ratio, h/ho (ft/ft) Po 8p" y bp~

bp~

bp- co CQ — P- CD QO. CD p to ro N o '

50, p H «Ao> "?f ^r£ . C•^

tpo_ Apache Monitor Well AP1TMW7 Recoveryl DATA SET: AP70I.INP 1. 02/14/12 AQUIFER TYPE: Uncanfin«d SOLUTION METHOD: Bouwvr«Rle« ESTIMATED PARAMETERS: K 0.09318 1 tlmi yO O.S027 ft c V TEST DATA: £ 0.1 HO - o.19 ri V re « 0.1687 ft _uo r« » 0.371 ft L « 10. ft V0I. t. > 150 ft H > 12.62 ft o o o o o

0.01 0. 0.05 0.1 0.15 0.2 Time (min)

STATISTICAL HATCH PARAMETER ESTIMATES: WEIGHTED RESIDUAL STATISTICS; Estimate Std. Error Number of residuals...... , 6 K = 9.3176E-002 +/- 1.1646E-002 Number of estimated parameters. , 2 yO = 6.0267E-001 +/- 1.0364E-001 Degrees of freedom...... , 4 Residual mean...... 0.003851 Residual standard deviation.... 0.01276 AMALYSIS OF MODEL RESIDUALS; Residual variance...... 0.0001629 residual = calculated - observed weighted residual = residual * weight MODEL RESIDUALS; Tim* Observed Calculated Residual Weight 0.0333 0.21 0.20418 0.0058216 1 0.05 0.11 0.11865 -0.0086505 1 0.0666 0.06 0.069174 -0.0091737 1 . 0.1 0.03 0.023359 0.0066406 1 0.1166 0.03 0.013619 0.016381 1 0.1333 0.02 0.0079139 0.012086 1 Head Ratio, h/ho (ft/ft) o

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rpo. Apache Monitor Well AP1TMW7 Falling Hd2 DATA SET: 9:apQ07.Inp 02'14/92 AQUIFER TYPE: Unconfin«d SOLUTION METHOD: Bouw«r-aict ESTIMATED PARAMETERS: K = 0.1681 ft/mm >0 » 3.164 ft c * ISO. ft H * 12.52 ft

I i, I 0.01 0. 0.05 0.1 0.15 0.2 Time (min)

STATISTICAL MATCH PARAMETER ESTIMATES; WEIGHTED RESIDUAL STATISTICS: Estimate Std. Error Number of residuals...... , 32 K = 1.6808E-001 +/- 5.1302E-003 Number of estimated parameters. 2 yO = 3.6642E+000 +/- 1.68965-001 Degrees of freedom...... 30 Residual mean...... 0.008538 Residual standard deviation.... 0.01111 ANALYSIS OF MODEL RESIDUALS; Residual variance...... 0.0001234 residual = calculated - observed weighted residual = residual * weight MODEL RESIDUALS; Time Observed Calculated Residual Weight 0.0233 0.95 0.93468 0.015322 1 0.0266 0.75 0.77025 -0.020245 1 0.05 0.2 0.19533 0.0046741 1 0.0666 0.07 0.073799 -0.0037988 1 0.0833 0.05 0.02772 0.02228 1 0.1 0.01 0.010412 -0.00041201 1 0.1166 0.01 0.0039339 0.0060661 1 0.15 0.01 0.00055502 0.009445 1 0.1833 0.01 7.8767E-005 0.0099212 1 0.2 0.01 2.9586E-005 0.0099704 1 0.2166 0.01 1.1178E-005 0.0099888 1 0.2333 0.01 4.1987E-006 0.0099958 1 0.25 0.01 1.5771E-006 0.0099984 1 0.2666 0.01 5.9587E-007 0.0099994 1 0.2833 0.01 2.2382E-007 0.0099998 1 0.3 0.01 8.4069E-008 0.0099999 1 0.3166 0.01 3.1763E-008 0.01 1 0.3333 0.01 1.1931E-008 0.01 1 0.4167 0.01 8.9728E-011 0.01 1 0.5 0.01 6.7879E-013 0.01 1 Head Ratio, h/ho (ft/ft) bP i i i

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O. TO Apache Monitor Well AP1TMW7 Recovery2 DATA SET: p:»p<]71 . inp 1. _ i i y i i i i i i i i i i i i i i i i _ 021 14132 L qo I AQUIFER TYPE: SOLUTION METHOD: - \ - B«uw«r -Rl c« ---^. \\ ESTIMATED PARAMETERS: «*-. K > 0.2383 rtlnln *-t \ yO » 9.727 ft C 0 0) \ TEST DATA: E 0.1 — \ — HO > 0.94 ft

STATISTICAL MATCH PARAMETER ESTIMATES; WEIGHTED RESIDUAL STATISTICS; Estimate Std. Error Number of residuals...... , 7 K 2.3827E-001 +/- 1.6262E-002 Number of estimated parameters. , 2 yO 9.7271E+000 V- 1.8864E+000 Degrees of freedom...... , 5 Residual mean...... , 0.005094 Residual standard deviation.... 0.01535 ANALYSIS OF MODEL RESIDUALS; Residual variance...... 0.0002357 residual = calculated - observed weighted residual = residual * weight HOPEI RESIDUALS; Time Observed Calculated Residual Weight 0.0333 0.61 0.61083 -0.00083186 1 0.05 0.16 0.15244 0.0075643 1 0.0666 0.02 0.038358 -0.018358 1 0.0833 0.01 0.0095725 0.00042748 1 0.1 0.02 0.0023889 0.017611 1 0.1166 0.02 0.00060113 0.019399 1 0.1333 0.01 0.00015001 0.00985 1 AP1TMW7 Rising Head Tesl2 \ \\ o aO:S 03)

0.01- 0.06 0.08 o.1 0.12 0.14 0.16 0.18 0.2 0.02 0.04 Time.t (mln) Water. Wast« & Land. Inc. Cl lent: ASARCO Project No.: 105 Location: Apache Tailings Monitor Well AP1TMW9 Recovery Test DATA SET: »p)QI.I up i. i i i i i i t i i 11 T i 11 i i | 11 i 11 i i i 11 i i i i t i r i i 03/CH'92 AQUIPER TYPE: unconrin«d SOLUTION METHOD: Bouw«r-Die* TEST DATE: Janulry 13. 1992 TEST WELL: »P1TM»3 ESTIMATED PARAMETERS C * 2.00Z4E-03 ft/mm 15o. »0 . 0.9(31 ft TEST DATA: HO • i.ai ft re . 0.375 ft r« . 05 ft L > 10. ft ft * I.2S ft M . I.JS ft

0.1 0. 100. 200. 300. 400. Time (min)

STATISTICAL MATCH PARAMETER ESTIMATES WEIGHTED RESIDUAL STATISTICS; Estimate Std. Error Number of residuals...... , 12 K = 2.00Z4E-005 +/- 8.7226E-Q07 Number of estimated parameters. , 2 yO = 9.6310E-001 +/- 1.2273E-002 Degrees of freedom...... , 10 Residual mean...... 0.001449 Residual standard deviation.... 0.02221 ANALYSIS OF MODEL RESIDUALS Residual variance...... 0.0004933 residual = calculated - observed weighted residual = residual * weight HOOEL RESIDUALS: Time Observed Calculated Residual Weight 5 0.99 0.94014 0.049864 1 10 0.93 0.91772 0.012284 1 20 0.86 0.87447 -0.014468 1 30 0.82 0.83326 -0.013258 1 40 0.77 0.79399 -0.02399 • 1 50 0.74 0.75657 -0.016573 1 60 0.7 0.72092 -0.020919 1 120 0.54 0.53964 0.0003646 1 180 0.42 0.40394 0.016062 1 240 0.32 0.30236 0.017637 1 300 0.28 0.22633 0.05367 0.1 372 0.21 0.15988 0.050118 0.1 Head Ratio, h/ho (ft/ft) po I I

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WORK PLAN CHANGE FORM

DATE: Janvary 10, 1992 WWL /1C6 : Hydroo.QOlcc:0 Work Plan, California Quloh EHs. SOP IHG-4, Procedures fo Conducting Suo; Tests

EXISTlNaWOBKPLAN SCOPE mEFEHENCi PAGE NUMSSO; SOPJHG-*,Procedunw!oi Ccndvctfrifl Slue T«at». Pwritfve dtepTacemtnt (faOing head} and neg«ti»o displacement (rUino head) «4ua> tests ere to b* performed fay frrtrodudofl er withdrawing, *e«0eetsvefy< a ayflndneal dog of thknowe icreenan voturnd t cic^onbto ,th * thewen l onloyr fpit snegativ wmetere . dUptecemarrtf the watei r tattovet l wfIl n thbea conduot«dw«R is fceloi W'Th thea slutogp wflofl b« Intrcducid or removed H ouloWy as posslbU to ooute, to the extent iittctfcW, tn insizntttllDUin wttss rCftino leyrie s Inunt thfnl watetrio rwsj» JflveJr lers. l A hapressurs stsbWzae transduced or 9r0 wilpercar.l b» t Mtrecovd to< rnsasury has t beathna CHANGE IN SCOPE: At Vrtfl* where th« small saturited thlcknau and slow recovsry t ma limit tha feasibility of p«rformIr)Q * ntgrtlva displacement tiuo tett a known-volume of \ rater ramovtd from tho w«8 by bailing or pumping instead of rarnovino a eyihdrical aiu< wffl be> tv«ou«ojd from the wefl as quieWy u po«ibl« to wpfAsem tnsuntanaot s 'to the extant practical. In atow rwovarlng walls, Instead of or h sddnwn to ha conditionUM of sa pr»»4vre transduow, water levels wtn be mawurtd at periodic lnt»rvai« wW a w«:i to a pnldalon of 0.01 'foot untfl the wntsr level eisfeSlzec or 90 pfireant recovery Is obtained. FOR CHANGE: In MveraJ cHh» vrelU rccsmiy rnitafied, tho rsoovcry of frsund water favftjl Is ralstfvtty slow. According to ttie original necetfve dhpfaotmont an i aJIowod to Irsrtsducar, sluv and etaodatod inatrurnantstlon vroald have to b« e pormh tht ramilwerttrn lavain

AftARCO 3IQMA7URE _/^"%2D^TB . DATE

: i£:6 : S6-02-I APPENDIX E PIPE CHEMICAL RESISTANCE INFORMATION

*&*-V ,-=;- -= , • • HANDBOOK OF PVC tlfE CHAPTER ID - RESISTANCE TO AGGRESSIVE ENVIRONMENTS No tuberculaiion means thai there is no reduction in flow areas and flow coefficients as PVC piping systems age. The long-term result of PVC 7. Geometry of piping system pipe's resistance to lubcrculation is reduced costs for operations and main- PVC Pipe: Resistance of PVC pipe to chemicals not generally found CruD in water and sewer systems is difficult to define. The chemical resistance t-» tenance. information for PVC pipe provided in Table 3.1 is based on short-term UD Internal corrosion due to sulfide generation in sanitary sewers has also immersion of unstressed strips of PVC in various chemicals (usually U) resulted in piping failures. A description of the vast nature of this problem undiluted). Results of this type of test can be used only as a guide to esti- with recommended solutions was provided in a paper entitled, "Case Histo- mate the response of PVC. It should be emphasized that the tables are -a ries of Sulfide Corrosion," by Schafer, Horner and Witzgall, which was meant as guidance to industrial purveyors of the chemicals listed, rather than usanitary sewer systems. As a result, no linings, coalings or cathodic pro- completed independent of that for the pipe. Because gasket and pipe mate- tection are required when PVC pipe is used. rials are different, so too are their abilities lo resist chemical attack. Simi- Different water and sewer pipe products provide corrosion resistance in larly, charts for resistance of gasket materials lo chemical attack are based varying degrees depending on application and environment. For this rea- on rubber manufacturers' testing and experience. The use of these charts is son, corrosion must be considered when selecting piping products. Be- complicated by (he fact that more than one elastomer may be present in a cause corrosive attack can be anticipated in most underground systems, rubber compound. Chemical resistance information for commonly used PVC pipe's corrosion immunity provides considerable savings in the form gaskel materials is found in Table 3.2. of reduced operating costs and increased system life. Charts covering all cases are not possible, there is no need for such charts. In applications where exposure to harmful chemicals is frequent, of CHEMICAL ATTACK long duration or in high concentrations, further testing is recommended. Resistance of PVC pipe and elastomeric gaskets to attack by chemical But for the vast majority of applications, PVC piping systems are not agents lias been determined through years of research and field experience. attacked by chemicals found in water and sewer systems. In general, PVC piping systems are not subject lo attack from chemicals The following chemical resistance legend is used in Tables 3.1 and 3.2: found in typical potable water and sanitary sewer systems. R = generally resistant Factors Affecting Resistance: Organo-chemical reactions can be Ul very complex. There are so many factors affecting the reaction of a piping C = less resistant than R but still suitable for some conditions CS system to chemical attack that it is impossible to construct charts lo cover all N - not resistant possibilities. Some of the factors affecting chemical resistance are: I 1. Temperature 2. Chemical (or ini xture of chemicals) present is 3. Concentration of chemicals T) 4. Duration of exposure • 5. Frequency of exposure cs 6. PVC compound (or rubber compound) present 26 27 I I I I I I I HANDBOOK OP PVC PIPE CHAPTER III • RESISTANCE TO AGGRESSIVE ENVIRONMENTS TABLE 3.1 TABLE 3.1 - Chemical Resistance of PVC Pipe - Continued CHEMICAL RESISTANCE OF PVC PIPE HE I4QF HE 140E ro Z3E liflE HE 140F CHEMKWl 22CJ I tfifld CHEMICAL (HO IMCJ CHEMICAL IHQ 1tfflC) CHFMICA1, oaci tfQC) Cane sugar liquors R R Cresol N N T N N Antimony trichloride R R Caibon bisulfide N N Cresylic acid, 50% R R U) Acetaldehyde C N Aquaregia C N Carbon dioxide R R Croton aldehyde N N in Acetaldehyde. aq 40% _ Carbon dioxide, aq Aeetamide m Atsenic acid, 10% R R R R Crude oU R R R R Aryl -sulfonic acid R R Carbon monoxide R R Cyclohexane N N ••O • Acetic «cid, vapor R N

TABLE 3.1 - Chemical Resistance of PVC Pipe - Continued _u HE CHBdrCAL uc 1 (fiflCl CHEMICAL I2JCJ (6QQ ? lUyoM coagulating biih R R Thread cunlnt oik R _ B Sea water R R Tcrpineol C C SaHcylic «cM R R Titanium lelrachtoritle C N SalkyUtd«hyde C C Toluene N N Selenlc Mid R R Tributyl phosphate N N Sewage. residential R R Silicic *cid R R Tiibulyl citrate R . Silkoae oil R N Tricrctyl phosphate N N Silver salti R R Trichloroacelic acid R R Soapa R R Tiichloroelhylene N N SodMHn s«ta, iq, except R R Tcietbanolaminc R C Sodium chlorite R R Tiicthylimine R R Sodium chloftle R C Trimeihy] propane R C Sodium dichfomale, acid R R Turpentine R R Sodium perborate R R U/ea R R Stannic chloiide R R Urine R R Slannmn chloride R R R R Vaielinc N N Steatk 4c!d R R Vegetable oils R R Stoddud N N Vinegar R R Vinyl acetate N N SulIiU li E N N N E N Cauxtlc Sod* E E fc E Acr.ionn N N N N N N C*u«tic *ota*ri E E E Atcnhoi (Mnthyl or CrxorWM (Dry) N N N N N N Elnyl) e N E N E E Cniorlo* (W*g N N N N N N Aluminum Cnioriese e E E C CMorlt* Bi««ch E N E N E E Aluminum Suliaie E E e E E E CWorotcetic Acid N N N N e E Aiumn e K E E E E ChloroM«2*n* N N N N Ammonia <5n» (Dry) e N N N E C Cnloroiofm N N N N N N Ammonium ChloridA E E E E E C Cnmmlc Acid I04t> E E E N C N Ammonium 1 lydrciidc E E E E E E Chromic Acid 9O>Vb E E N N N N Citric Acid E E E E C E Ammonium Nitr.irn 6 E E E E E Copper CmorxJe E C E E E E Ammomum Coppar Cyanide E E E £ Phosphate E E E E E C Copper Nitrate E E E E E E Ammonium Sui'ate E e E E E E Ammonium Suiride E f. E E E E Copper Surrsi" E E E E E E Amyl Cnlorid* N N N N Cononsmd On E E e C Crcso! N N N N E N Anilma N N N N N N Cyclohaxanol N N N N N N Aq.1,1 HcKjia N N E G CycJohoxanone N N N N N N Barium Chlondn E E E E E E Barium Dimethylamino E E Hydroxide 10"* £ E E E Oioctylphthalatc N N N N N N Barium Sulfaio E E E E Oisodium Phosphate E E E Qarium Sullidc E * E E E Dietilled Water E 6 E E E E Beer E E N E E Ethers N N N N N N Oool Sugar Liquors E E frnnrono N N N N N N Ethyl AcvtaW N N N N N N H»n*oic Acid E E E E E E Elhylvn* Chloride N N N N Elhylvn* Glycol E F E E Block IjQuor E E E N E E Fwtjr Acids (C. N N 6 E E E Hl»acn-1?.5on Bi*ul'>d» N N N N Hydrobromk Guroon nio»lo> E Acid 204k E E E N e E Cnrnon Monoxide e e e e e E Hydrochloric; Acid E E E N E E Carbon e e Hydrocyanic Acid C C E E E E letracnlorida N N N N E N Hydrarluric Acid (10) C C C N C G Ratings: C No attack Q No appreciable attack N Not recommended flUG-28-1995 503 984 4750 P.06

Plastic Pipe Institute 3 Plastic Pipe Institute 4 Polyethylene ASS PVC Poryeihylen* ABS PVC Reagent 73«F 120«F 7TF 1WF 73«F WO^F Reagent 73V law 73»F 160»F 73»F 140»F Hydrogen Se*w»t»f E E E E E E P»ro»'Ce 9041) E E Sewerage E E E E E 6 Hy E E N N E E Sulftte Liquor E E E C E E Nitric ACKI (4OU>) C G N N C C Sulfur E E E Sulfur Dioxide OH. Crii E E E e e E Carbonate E E E E E E Water (Salt) E E E e E E Potassium Chlorate E E E E E E Whiskey E E E Potas.TJbfli Chloride E E E E E E Potassium Cyanide E E E While Liquor f E E N E E Polar sium win«» E E N E E Diul>ru/"al* E E C Xyl»n« C N N N N 2irtc Cnionde E C E E E E Pow»*iurn Zinc Sulfale E E E E E E Hydroxide • t S E E Pnrauium Par- e manganale 10% E E E Potassium Su'faie E E E E E E P'o0«i'* Ca> E E Propyl Alcohol E N E E NOTE: The data listed in this Bulletin Is only to give information in regard to general use and does not constitute a guarantee. Materials should b* tested unaor actual service to determine suitability for a panicular purpose. Reorder No. 692 3/92