STATE OF ARIZONA AQUIFER PROTECTION PERMIT NO. P PLACE ID , LTF 49639

Transcription

1 1.0 AUTHORIZATION STATE OF ARIZONA AQUIFER PROTECTION PERMIT NO. P PLACE ID , LTF In compliance with the provisions of Arizona Revised Statutes (A.R.S.) Title 49, Chapter 2, Articles 1, 2 and 3, and Chapter 4, Arizona Administrative Code (A.A.C.) Title 18, Chapter 9, Articles 1 and 2, A. A. C. Title 18, Chapter 11, Article 4 and amendments thereto, and the conditions set forth in this permit, Rosemont Copper Company is hereby authorized by the Arizona Department of Environmental Quality (ADEQ) to operate the Rosemont Copper Mine facility located in Pima County, Arizona, over groundwater of the Cienega Creek groundwater basin in portions of Township 18 South, Range 15 and 16 East of the Gila and Salt River Base Line and Meridian. This permit becomes effective on the date of the Water Quality Division and Waste Programs Division Directors signatures and shall be valid for the life of the facility (construction. operational, closure, and post-closure periods), unless suspended or revoked pursuant to A.A.C. R18-9-A213. The permittee shall construct, operate and maintain the permitted facilities: 1. Following all the conditions of this permit including the design and operational information documented or referenced below, and 2. Such that Aquifer Water Quality Standards (AWQS) are not violated at the applicable point(s) of compliance (POC) set forth below, or if an AWQS for a pollutant has been exceeded in an aquifer at the time of permit issuance, that no additional degradation of the aquifer relative to that pollutant, and as determined at the applicable POC, occurs as a result of the discharge from the facility. 1.1 PERMITTEE INFORMATION Facility Name: Facility Address: Rosemont Copper Project S. Sonoita Highway Vail, AZ Permittee: Rosemont Copper Company Permittee Address: 4500 Cherry Creek South Dr., Suite 1040 Denver, Colorado Facility Contact: Katherine Arnold Emergency Phone No.: (520) Latitude/Longitude: 31º 50 N / 110º 45 W Legal Description: Township 18S, Range 16E, Sections 19, 20, 21, 22, 28, 29, 30, 31, 32, and 33; Township 19S, Range 16E, Sections 5 and 6; Township 18S, Range 15E, Sections 24, 25, and 36; of the Gila and Salt River Base Line and Meridian 1.2 AUTHORIZING SIGNATURE Michael A. Fulton, Director Amanda E. Stone, Director Water Quality Division Waste Programs Division Arizona Department of Environmental Quality Arizona Department of Environmental Quality Signed this day of, 2011 Signed this day of, 2011

2 2.0 SPECIFIC CONDITIONS [A.R.S (4), (A)] AQUIFER PROTECTION PERMIT NO. P p. 2 of Facility / Site Description [A.R.S (K)(8)] The Rosemont Copper Project (Rosemont) is facility consisting of an open-pit mining and mineral processing facility located approximately 30 miles southeast of Tucson, Arizona. Rosemont operations include conventional crushing and flotation of sulfide ore to produce copper and molybdenum concentrate to be transported offsite for further processing, as well as heap leaching of oxide ore and solution extraction/electrowinning facilities. Further descriptions of these facilities can be found in Table Dry Stack Tailings Facility The Dry Stack Tailings Facility consist of two separate areas referred to as the North Stack and South Stack. The South or Phase 1 Stack, is designed to accommodate about 343 million tons of dry stack tailings and the North or Phase 2 Stack about 253 million tons. The Dry Stack Tailings facilities shall receive dry stack tailings at a nominal rate of about 75,000 tons per day. The tailings material shall be stacked behind large waste rock buttresses. The Dry Stack Tailings Facility shall receive filtered (dewatered) tailings from the Tailings Filter Plant. The filter plant shall receive tailings slurry from the Copper-Molybdenum flotation circuit Primary Settling Basin The Primary Settling Basin shall be located in the Plant Site area and shall receive process materials consisting of un-filtered tailings (slurry) on a short-term basis. The PSB has a surface area of approximately 8.41 acres and a volume capacity of approximately 61.4 million gallons with a minimum 2-feet of freeboard Process Water Temporary Storage Pond The Process Water Temporary Storage (PWTS) Pond shall be located in the Plant Site area and is divided into two sections identified as the Process Water (PW) Pond and the Temporary Storage (TS) Pond. The PW Pond shall be a double-lined surface impoundment that provides a minimum 24-hour storage of water for the mineral processing circuit. Water in the PW pond shall consist of makeup and process water, including potential overflow from the Primary Settling Basin. The PW Pond also provides emergency storage in case of a service interruption at the plant facilities. The TS Pond shall be a single-lined surface impoundment that receives stormwater runoff and also shall provide emergency overflow containment for the PW Pond. The PW Pond shall have a storage capacity of approximately 69.7 million gallons, including 2 feet of freeboard. The capacity to the freeboard limit shall be approximately 62.4 million gallons. The TS Pond shall have a storage capacity of approximately 38.1 million gallons, including 2 feet of freeboard. The capacity to the freeboard limit shall be approximately 34.2 million gallons Raffinate Pond The Raffinate Pond shall be located in the Plant Site area, immediately northwest and up-gradient of the PWTS Pond, and shall be a double-lined surface impoundment. Barren solution from the Solvent Extraction/Electrowinning (SX/EW) Plant shall be acidified in the Raffinate Pond and pumped to the top of the stacked ore located on the Heap Leach Pad. The pond shall have a storage capacity of approximately 3.6 million gallons, which includes 3 feet of freeboard. The capacity to the freeboard limit shall be approximately 2.8 million gallons Heap Leach Pad The Heap Leach Pad (Phase 1 and Phase 2) shall be constructed southeast of the Open Pit within the Barrel Canyon drainage. Oxide Ore excavated from the Open Pit shall be generally placed on the Heap Leach Pad in approximate 30-foot lifts and irrigated with raffinate using drip emitters. The Heap Leach Pad liner shall consist of a 60-mil linear low density polyethylene (LLDPE) liner on top of a GCL. Pregnant leach solution, or PLS, shall gravity drain from the pad via perforated drain pipelines designed to route solutions to the PLS Pond through a collection pipeline system. The system also includes a Stormwater Pond that shall be connected to the PLS Pond. It is anticipated that run-of-mine

3 p. 3 of 45 (ROM) oxide ore shall be stacked on the Heap Leach Pad. Ore can be stacked to a maximum height of 450 feet above the liner PLS Pond The PLS Pond shall be located near the northeast corner of the Heap Leach Pad, adjacent to the Stormwater Pond, and shall be a double-lined surface impoundment. The pond shall receive PLS from the Heap Leach Pad before solution is pumped to the SX/EW Plant for processing. The pond shall have a storage capacity of approximately 22.8 million gallons, which includes a freeboard limit of three feet. The capacity to the freeboard limit shall be approximately 18.9 million gallons Stormwater Pond The Stormwater Pond shall be located northeast of the Heap Leach Pad, immediately adjacent to the PLS Pond, and shall be a single-lined surface impoundment. The Stormwater Pond shall be connected to the PLS Pond via a spillway, and as a result, may contain stormwater runoff from the Heap Leach Pad and PLS from overflow of the PLS Pond during storm events. However, the Stormwater Pond shall typically be empty during normal operating conditions. The pond shall have a storage capacity of approximately 31.6 million gallons, including 3 feet of freeboard. The capacity to the freeboard limit is approximately 26.4 million gallons Waste Rock Storage Area The Waste Rock Storage Area shall be constructed southeast/east of the Open Pit within the Barrel Canyon drainage system and shall receive waste rock from development of the Open Pit. The overall footprint for the area is approximately 1370 acres and consists of approximately 756 million tons of waste rock Waste Management Area (Non-Municipal Solid Waste Landfill) The Waste Management Area shall be located northwest of the Plant Site and shall be comprised of a private non-municipal solid waste landfill with an approved waste footprint of approximately 2.6 acres for the disposal of non-hazardous wastes generated on-site. The following wastes are acceptable for disposal in the Waste Management Area: a. Clean Fill: Clean rock (no acid-generating materials) and soil. b. Construction and Demolition Debris: as defined in A.R.S (5) and (7). c. Inert Material: as defined in A.R.S (15). d. Landscape Rubble: as defined in A.R.S (17). e. Vegetative Waste: as defined in A.R.S (36). f. Rubbish: as defined in A.A.C. R (H). g White Goods: Prior to disposal, chlorofluorocarbon (CFC)-containing appliances will conform to the requirements of Title 40 of CFR 82 Subparts E and F. h. Empty metal containers. i. Dry paper and cardboard. j. Plastic containers and products. k. Glass. This facility shall not receive any wastes generated off-site and shall conform to the standards of a non-municipal solid waste landfill facility. Municipal solid waste, tires, batteries, septage, regulated friable asbestos containing material, and sewage sludge are prohibited for disposal at the landfill. The excavation depth will range between 5 and 43 feet deep with a minimum excavation elevation of approximately 5,190 feet above mean sea level (amsl) at the toe of the northeastern fill slope; the lowest elevation of waste placement will be at approximately 5,234 feet amsl. The maximum height of the landfill at final closure shall be no more than 5,280 feet amsl.

4 p. 4 of 45 This permit authorizes the construction and operation of the following discharging facilities: TABLE 2.1 Facilities Facility Latitude Longitude Dry Stack Tailings Facility 31º º Process Water Temporary Storage Pond 31º º Primary Settling Basin 31º º Raffinate Pond 31º º Heap Leach Pad 31º º PLS Pond 31º º Stormwater Pond 31º º 44 9 Waste Rock Storage Area 31º º Waste Management Area (Non-Municipal Solid Waste Landfill) 31º º 45 4 Annual Registration Fee [A.R.S ] The annual registration fee for this permit is established by A.R.S and is payable to ADEQ each year. The design flow is in excess of 10,000,000 gallons per day (gpd). The annual registration fee for the Non-Municipal Solid Waste Landfill is established by A.R.S (C)(7) and the landfill disposal fees are established by A.R.S based on the amount of waste landfilled. The fees are payable to ADEQ each year. Financial Capability [A.R.S (N) and A.A.C. R18-9-A203] The permittee has demonstrated financial capability under A.R.S (N) and A.A.C. R18-9-A203. The permittee shall maintain financial capability throughout the life of the facility. The estimated closure and postclosure costs for the facilities listed in this area-wide APP are $2,744,100 and $1,549,035. The Dry Stack Tailings Facility shall undergo concurrent reclamation as practicable, which is covered as part of the annual operational costs. Financial assurance was demonstrated through A.A.C. R18-9-A203(C)(2) through a Surety Bond from Arch Insurance Company. 2.2 Best Available Demonstrated Control Technology [A.R.S (B) and A.A.C. R18-9-A202(A)(5)] The construction and operational parameters listed in Sections 2.2 and 2.2.1, in addition to the design criteria and site characteristics described in the APP application referenced in Section 5.0, constitute BADCT for this facility and shall be constructed, operated, and maintained as described therein Engineering Design

5 p. 5 of 45 All of the facilities listed in Table 2.1 have been evaluated and determined to meet the requirements of A.R.S and A.A.C. R18-9-A202. Specific design details for each facility are listed in Section 4, Table Site-specific Characteristics Not applicable Pre-operational Requirements Subgrade Preparation and Testing A Quality Assurance Engineer (QAE) shall be responsible for applicable Quality Assurance (QA) work related to subgrade preparation and testing. The QAE shall be an Arizonaregistered Professional Engineer. The QAE shall be responsible for certifying that the subgrade preparation and testing was performed according to approved specifications in the application documents. The certification shall be included in the report required under the Compliance Schedule, Section Liner Installation and Testing A QAE shall be responsible for applicable QA work related to liner installation and testing. The QAE shall be a third party Arizona-registered Professional Engineer. The QAE shall be responsible for reporting and certifying that the liner installation and testing was performed according to approved specifications in the application documents. The certification shall be included in the report required under the Compliance Schedule, Section Underdrain System Installation and Testing A QAE shall be responsible for applicable QA work related to underdrain installation and testing. The QAE shall be an Arizona-registered Professional Engineer. The QAE shall be responsible for reporting and certifying that the underdrain system installation and testing was performed to approved specifications in the application documents. The certification shall be included in the report required under the Compliance Schedule, Section Operational Requirements Permittee shall perform inspections and operational monitoring as required in Section 4, Table If damage is identified during an inspection that could cause or contribute to a discharge, proper repairs shall be promptly performed. The Action Leakage Rates (AL 1) and Rapid and Large Leakage Rates (AL2) are established as follows: Concurrent Reclamation of Dry Stack Tailings Facility The permittee shall reclaim portions of the outer slopes of the Dry Stack Tailings Facility concurrent with on-going mine operations as described in the application documents referenced in Section 5 of the permit. TABLE 2.2 Leak Collection and Removal System (LCRS) Monitoring Note: The Alert Level 1 (AL1) or Alert Level 2 (AL2) shall be exceeded when the amount of leakage pumped from the sump for the pond is greater than the applicable quantity below. For reporting purposes on the SMRF, the AL1 is equivalent to the Alert Level and AL2 is equivalent to the DL. An exceedance of the DL is not a violation of the permit unless the permittee fails to perform as required under Section

6 AL1 gallons per day (gpd) AL2 gallons per day (gpd) AQUIFER PROTECTION PERMIT NO. P p. 6 of 45 Monitoring Method Monitoring Frequency Reporting Frequency LCRS Sump Parameter PW (PWTS) Pond (PW Portion) Liquid Pumped [1] 3,859 82,143 Visual Daily Quarterly Raffinate Pond 411 8,751 Visual Daily Quarterly PLS Pond 1,797 38,239 Visual Daily Quarterly At a minimum, permitted facilities shall be inspected for performance levels listed in Section 4, Table Results of these inspections and monitoring activities shall be documented and maintained at the mine location for at least 10 years, and as required by Section of this permit. If damage is identified during an inspection that could cause or contribute to an unauthorized discharge, proper repairs shall be promptly performed. A summary of the repairs, including a description of the procedures and materials used shall be maintained with the inspection records noted above. 2.3 Discharge Limitations [A.R.S (14), and A.A.C. R18-9-A205(B)] The permittee shall operate and maintain all permitted facilities listed below to prevent unauthorized discharges pursuant to A.R.S (12) resulting from failure or bypassing of BADCT pollutant control technologies including liner failure 1, uncontrollable leakage, overtopping (e.g., exceeding the maximum storage capacity, defined as a fluid level exceeding the crest elevation of a permitted impoundment), berm breaches that result in an unexpected loss of fluid, accidental spills, or other unauthorized discharges. The discharge limitations in this section are not applicable to any discharge caused by precipitation in excess of a single 100-year/24 hour storm event or process overflow during a power outage exceeding 24 hours in duration Leaching Facilities The Leaching Facilities are designed and authorized for use in leaching of ore. The Leaching Facilities shall be constructed and operated in accordance with the BADCT outlined in Section 4, Table 4.1.1, and the ultimate heights shall not exceed those set forth in the approved permit application and engineering study Pregnant Leach Solution Ponds and Other Impoundments The PLS Pond, Raffinate Pond, Primary Settling Basin, and the PWTS Pond are designed and authorized to receive, as specified in this permit, PLS, barren leach solution, raffinate, stormwater, process water, makeup water, and process upset events Non-stormwater Impoundment The permitted non-stormwater impoundment (referred to by the permittee as the Storm water Pond) is authorized to receive stormwater runoff and runon, and process solutions as a result of storm events or process upset events. 2.4 Point(s) of Compliance [A.R.S ] 1 Liner failure in a single-lined impoundment is any condition that would result in a leakage exceeding 550 gallons per day per acre.

7 The POC(s) are established by the following monitoring location(s): AQUIFER PROTECTION PERMIT NO. P p. 7 of 45 TABLE 2.4 POC Well Locations POC Locations Latitude (Approximate) Longitude (Approximate) POC #1 31º º POC #2 31º º POC #3 31º º POC #4 31º º POC #5 31º º POC #6 31º º POC #7 31º º Monitoring requirements for each POC well are listed in Section 4.2, Tables and The Director may amend this permit to designate additional POCs, if information on groundwater gradients or groundwater usage indicates the need. 2.5 Monitoring Requirements [A.R.S (B) and (K)(1), A.A.C. R18-9-A206(A)] All monitoring required in this permit shall continue for the duration of the permit, regardless of the status of the facility. All sampling, preservation and holding times shall be in accordance with currently accepted standards of professional practice. Trip blanks, equipment blanks and duplicate samples shall also be obtained, and Chain-of-Custody procedures shall be followed, in accordance with currently accepted standards of professional practice. The permittee shall develop a site specific Quality Assurance Project Plan (QAPP) that describes the sample collection and analysis procedures to ensure that the result of work performed under this permit will satisfy the data quality objectives of the permit. The permittee shall be responsible for the quality and accuracy of all data required by this permit. If a third party collects or analyzes samples on behalf of the permittee, the permittee shall obtain a copy of the third party site specific QAPP. The permittee shall consult with the most recent version of the ADEQ Quality Assurance Program Plan and Title 40, PART 136 of the Environmental Protection Agency s (EPA) Code of Federal Regulations (CFR) for guidance in this regard. Copies of laboratory analyses and Chain-of-Custody forms shall be maintained at the permitted facility. Upon request, these documents shall be made immediately available for review by ADEQ personnel Discharge Monitoring Not applicable for this permit Facility / Operational Monitoring The operational monitoring requirements for the facilities referenced in Section 4, Table are listed in Section 4, Table Groundwater Monitoring and Sampling Protocols Static water levels shall be measured and recorded prior to sampling. Wells shall be purged of at least three (3) borehole volumes (as calculated using the static water level) or until field parameters (ph, temperature, conductivity) are stable, whichever represents the greater volume. If evacuation results in the well going dry, the well shall be allowed to recover to 80% of the original borehole volume, or for 24 hours, whichever is shorter, prior to sampling. If after 24 hours there is not sufficient water for sampling, the well shall be recorded as dry for the monitoring event. An explanation for reduced pumping volumes, a record of the volume pumped, and modified sampling procedures shall be reported and submitted with the Self- Monitoring Report Form (SMRF). Alternatively, the permittee may conduct sampling using the low-flow purging method as described in

8 p. 8 of 45 the ASTM International Standard D , and EPA Groundwater Issue 540/S-95/504 Low-Flow (Minimal Drawdown) Groundwater Sampling Procedures. The well must be purged until indicator parameters stabilize. Indicator parameters shall include ph, temperature, specific conductance, oxidation-reduction potential, dissolved oxygen and turbidity. Due to extensive screen length, POC #5 (RP-4) must be sampled using this alternative method. If the water table in this groundwater monitor well rises to a level above the screened interval, the well must be replaced. Alternatively, the permittee may initially elect to install a new well at this location with a modified screen length and avoid low-low purging methods POC Well Installation Groundwater monitor wells must be installed at POC locations POC #1, POC #2, POC #3, POC #4, POC #5 if re-installed, POC #6, and POC #7, in accordance with the Compliance Schedule, Section POC Well Replacement In the event that one or more of the designated POC wells should become unusable or inaccessible due to damage, insufficient water in the well for more than 2 (two) sampling events, or any other event, a replacement POC well shall be constructed and installed upon approval by ADEQ. If the replacement well is fifty (50) feet or less from the original well, the ALs and/or AQLs calculated for the designated POC well shall apply to the replacement well. Otherwise, the ALs and/or AQLs shall be set following the provisions in Section and Section of this permit Ambient Groundwater Quality Monitoring for POC Wells Eight (8) quarters of groundwater sampling are required to establish ambient groundwater quality in all POC groundwater monitoring wells (POC#1 through POC#7), in accordance with the Compliance Schedule, Section 3.0. Each quarterly sample shall be analyzed for the parameters listed in Section 4, Table Alert levels and aquifer quality limits shall be established as required in Sections and Alert Levels for POC Wells AQLs and ALs for POC wells will be calculated for all parameters listed in Section 4, Table with an established AWQS, based on the eight (8) quarterly groundwater samples as required in the compliance schedule. Within 90 days of receipt of the laboratory analyses for the final quarter of the ambient groundwater monitoring period for each POC well, the permittee shall submit the ambient groundwater monitoring data in tabulated form to the ADEQ Groundwater Section (GWS) for review. Copies of all laboratory analytical reports, field notes, and the Quality Assurance/Quality Control (QA/QC) procedures used in the collection and analyses of the samples for all parameters listed in Section 4, Tables and shall be submitted to the GWS. The permittee may submit a report with the calculations for each AQL and AL included in the permit for review and approval by ADEQ, or the permittee may defer calculation of the AQLs and ALs to the GWS. The AQLs and ALs shall be established and calculated by the following formula or another valid statistical method submitted to GWS in writing and approved for this permit by the GWS: AL = M + KS Where M = mean, S= standard deviation, and K = one-sided normal tolerance interval with a 95% confidence level (Lieberman, G.J. (1958) Tables for One-sided Statistical Tolerance Limits: Industrial Quality Control, Vol. XIV, No. 10). Obvious outliers should be excluded from the data used in the AL calculation. The following criteria shall be met in establishing ALs in the permit:

9 p. 9 of The AL shall be calculated for a parameter using the analyses from a minimum of eight (8) consecutive quarterly sample rounds. The permittee shall not use more than eight (8) sample rounds in the calculation. 2. Any data where the practical quantification limit (PQL) exceeds 80% of the AWQS shall not be included in the AL calculation. 3. If a parameter is below the detection limit, the permittee must report the value as less than the numeric value for the PQL or detection limit for the parameter, not just as non-detect. For those parameters, the permittee shall use a value of one-half the reported detection limit for the AL calculation. 4. If the analytical results from more than 50% of the samples for a specific parameter are non-detect, then the AL shall be set at 80% of the AWQS. 5. If the calculated AL for a specific constituent and well is less than 80% of the AWQS, the AL shall be set at 80% of the AWQS for that constituent in that well Aquifer Quality Limits for POC Well For each of the monitored analytes for which a numeric AWQS has been adopted, the AQL shall be established as follows: 1. If the calculated AL is less than the AWQS, then the AQL shall be set equal to the AWQS. 2. If the calculated AL is greater than the AWQS, then the AQL shall be set equal to the calculated AL value, and no AL shall be set for that constituent at that monitoring point Compliance Groundwater Quality Monitoring for POC Wells Quarterly compliance groundwater monitoring in the remaining POC wells shall commence beginning the first calendar quarter after the completion of the ambient sampling period for that well. For quarterly compliance monitoring, the permittee shall analyze groundwater samples for the parameters listed in Section 4, Table In addition to quarterly compliance groundwater monitoring, every two (2) years (biennial) the permittee shall analyze samples from the POC wells for an expanded list of parameters listed in Section 4, Table The biennial sampling event shall replace the regularly scheduled quarterly sampling event for the quarter in which the biennial sampling event is conducted Surface Water Monitoring and Sampling Protocols Not applicable for this permit Analytical Methodology All groundwater samples collected for compliance monitoring shall be analyzed using Arizona stateapproved methods. If no state-approved method exists, then any appropriate EPA-approved method shall be used. Regardless of the method used, the detection limits must be sufficient to determine compliance with the regulatory limits of the parameters specified in this permit. Analyses shall be performed by a laboratory licensed by the Arizona Department of Health Services, Office of Laboratory Licensure and Certification. For results to be considered valid, all analytical work shall meet quality control standards specified in the approved methods. A list of Arizona state-certified laboratories can be obtained at the address below: Arizona Department of Health Services Office of Laboratory Licensure and Certification 250 North 17 th Avenue Phoenix, AZ Phone: (602) Installation and Maintenance of Monitoring Equipment

10 p. 10 of 45 Monitoring equipment required by this permit shall be installed and maintained so that representative samples required by the permit can be collected. If new groundwater wells are determined to be necessary, the construction details shall be submitted to the ADEQ Groundwater Section for approval prior to installation and the permit shall be amended to include any new points. 2.6 Contingency Plan Requirements [A.R.S (K)(3), (K)(7) and A.A.C. R18-9-A204 and R18-9-A205] General Contingency Plan Requirements At least one copy of this permit and a contingency and emergency response plan shall be maintained at the location where day-to-day decisions regarding the operation of the facility are made. A contingency plan shall be submitted to ADEQ pursuant to the compliance schedule in Section 3.0. The permittee shall be aware of and follow the contingency and emergency plans. Any AL that is exceeded or any violation of an AQL, DL, or other permit condition shall be reported to ADEQ following the reporting requirements in Section Some contingency actions may involve verification sampling. Verification sampling shall consist of the first follow-up sample collected from a location that previously indicated a violation or the exceedance of an AL. Collection and analysis of the verification sample shall use the same protocols and test methods to analyze for the pollutant or pollutants that exceeded an AL or violated an AQL. The permittee is subject to enforcement action for the failure to comply with any mandatory contingency actions in this permit. Where verification sampling is specified in this permit, it is the option of the permittee to perform such sampling. If verification sampling is not conducted within the timeframe allotted, ADEQ and the permittee shall presume the initial sampling result to be confirmed as if verification sampling has been conducted. The permittee is responsible for compliance with contingency plans relating to the exceedance of an AL or violation of a DL, AQL or any other permit condition Exceeding of Alert Levels Exceeding of Alert Levels Set for Operational Conditions 1 Performance Levels Set for Freeboard In the event that freeboard alert levels established in Table in a surface impoundment are not maintained, the permittee shall: a. As soon as practicable, cease or reduce discharging to the impoundment to prevent overtopping. Remove and properly dispose or recycle to other operations the excess fluid in the reservoir until the water level is restored at or below the permitted freeboard limit. b. Within 5 days of discovery, evaluate the cause of the incident and adjust operational conditions as necessary to avoid future occurrences. c. Record in the facility log, the amount of fluid removed, a description of the removal method, and the disposal arrangements. The facility log shall be maintained according to Section (Operational Inspection/Log Book Recordkeeping). Records documenting each freeboard incident and actions taken to correct the problem shall be included in the current report as required in Section (Self Monitoring Report Forms). d. The facility is no longer on alert status once the operational indicator no longer indicates that the freeboard performance level is being exceeded. The permittee shall, however, complete all tasks necessary to return the facility to its pre-alert operating condition.

11 2. Performance Levels, Other Than Freeboard AQUIFER PROTECTION PERMIT NO. P p. 11 of 45 a. If an operational AL listed in Section 4, Table has been observed or noted during required inspection and operational monitoring, such that the result could cause or contribute to an unauthorized discharge, the permittee shall immediately investigate to determine the cause of the condition. The investigation shall include the following: 1. Inspection, testing, and assessment of the current condition of all treatment or pollutant discharge control systems that may have contributed to the operational performance condition. 2. Review of recent process logs, reports, and other operational control information to identify any unusual occurrences. b. The AL exceedance, results of the investigation, and any corrective action taken shall be reported to the Water Quality Compliance Section (WQCS), within thirty (30) days of the discovery of the condition. Upon review of the submitted report, the Department may amend the permit to require additional monitoring, increased frequency of monitoring, or other actions. c. The permittee shall initiate actions identified in the approved contingency plan referenced in Section 3 and any specific contingency measures identified in Section 2.6 to resolve any problems identified by the investigation which may have led to an AL being exceeded. To implement any other corrective action the permittee shall obtain prior approval from ADEQ according to Section Exceeding of Alert Levels Set for Discharge Monitoring Not applicable to this permit Exceeding of Alert Levels in Groundwater Monitoring Alert Levels for Indicator Parameters Not applicable to this permit Alert Levels for Pollutants with Numeric Aquifer Water Quality Standards 1. If an AL for a pollutant set in Section 4.2, Tables or has been exceeded, the permittee may conduct verification sampling within 5 days of becoming aware of an AL exceedance. The permittee may use the results of another sample taken between the date of the last sampling event and the date of receiving the result as verification. 2. If verification sampling confirms the AL exceedance or if the permittee opts not to perform verification sampling, then the permittee shall increase the frequency of monitoring to monthly. In addition, the permittee shall immediately initiate an investigation of the cause of the AL exceedance, including inspection of all discharging units and all related pollution control devices, review of any operational and maintenance practices that might have resulted in an unexpected discharge, and hydrologic review of groundwater conditions including upgradient water quality from existing wells. 3. The permittee shall initiate actions identified in the approved contingency plan referenced in Section 3.0 and specific contingency measures identified in Section 2.6 to resolve any problems identified by the investigation which may have led to an AL exceedance. To implement any other corrective action the permittee shall obtain prior approval from ADEQ according to Section Alternatively, the permittee may

12 p. 12 of 45 submit a technical demonstration, subject to written approval by the Groundwater Section, that although an AL is exceeded, pollutants are not reasonably expected to cause a violation of an AQL. The demonstration may propose a revised AL or monitoring frequency for approval in writing by the Groundwater Section. 4. Within 30 days after confirmation of an AL exceedance, the permittee shall submit the laboratory results to the Water Quality Compliance Section along with a summary of the findings of the investigation, the cause of the AL exceedance, and actions taken to resolve the problem. 5. Upon review of the submitted report, the Department may amend the permit to require additional monitoring, increased frequency of monitoring, or other actions. 6. The increased monitoring required as a result of an AL exceedance may be reduced to the regular frequency, if the results of three (3) sequential sampling events demonstrate that no parameters exceed the AL. 7. If the increased monitoring required as a result of an AL exceedance continues for more than six (6) sequential sampling events, the permittee shall submit a second (2 nd ) report documenting an investigation of the continued AL exceedance within 30 days of the receipt of laboratory results of the sixth (6 th ) sampling event Alert Levels to Protect Downgradient Users from Pollutants without Numeric Aquifer Water Quality Standards Not applicable Exceedance of LCRS Alert Level 1 (AL1) If an Alert Level 1 (AL 1) as specified in Section 2.2.4, Table 2.2, has been exceeded, the permittee shall take the following actions: 1. Within five (5) days of discovery, determine if the fluid in the collection sump is operational/process water from the impoundment by measuring the ph and conductivity of fluids in the impoundment and in the sump to allow for a direct comparison in water quality. Notify ADEQ Water Quality Compliance Section, Enforcement Unit, in accordance with Section (Permit Violation and AL Status Reporting), and include in the notification an assessment of the type of water in the sump. Monitor fluid removal from the LCRS on a daily basis until the daily volume of fluid quantified remains below AL1 for 30 days in order to minimize the hydraulic head on the lower liner. 2. Within 15 days, assess the condition of the liner system using visual methods for visible portions of the liner. If linerdamage is evident, the permittee shall complete liner repairs and submit documentation of the repairs in the initial report discussed in Item No. 3 below. 3. Within 30 days of discovery of exceeding AL1, the permittee shall submit an initial report to ADEQ Water Quality Compliance Section to address problems identified from the initial assessment of the liner system, the source of the fluid, and any remedial actions taken to minimize the future occurrences. The report shall include the results of the initial liner evaluation, methods used to locate the leak(s) if applicable, any repair procedures implemented to restore the liner to optimal operational status if required, and other information necessary to ensure the future occurrence of the incidence will be minimized. The permittee shall also submit the report required under Section Exceedance of LCRS Alert Level 2 (AL2 or DL) If the Liner Leakage Discharge Limit (AL 2) specified in Section 2.2.4, Table 2.22, has been exceeded, the permittee shall: 1. Immediately cease all discharge to the impoundment, and notify ADEQ s Water Quality Compliance Section orally, electronically, or, by facsimile, of the AL2 exceedance.

13 p. 13 of 45 Within 24 hours, determine if water in the collection sump is operational/process water from the impoundment by measuring the ph and conductivity of fluids contained in the impoundment and in the sump to allow direct comparison in water quality. 2. Within 5 days of discovery, notify ADEQ Water Quality Compliance Section, in accordance with Section (Permit violation and AL Status Reporting) and include an assessment regarding the type of water in the sump based upon the measurements taken according to Item No. 1 listed above. 3. Within 15 days of discovery identify the location of the leak(s) using visual methods, electrical leak detection, or other methods as applicable. If liner damage is evident, the permittee shall complete liner repairs and submit documentation of the repairs in Item No. 4 below. Discharge to the impoundment shall not be re-initiated until the leak(s) have been identified and repaired. 4. Within 30 days of exceeding AL2, submit a report to ADEQ as specified in Section (Permit Violation and AL Status Reporting). The report shall include the results of the initial liner evaluation, methods used to locate the leak(s) if applicable, any repair procedures and quality assurance/quality control implemented to restore the liner to optimal operational status if required, and other information necessary to ensure the future occurrence of the incidence will be minimized. Upon review of the report, ADEQ may request additional monitoring or remedial actions. 5. If AL2 continues to be exceeded following completion of repairs, submit for approval to ADEQ, a corrective action plan including a schedule to complete the corrective actions to address all problems identified from the assessment of the liner system and surface releases, if any, within 60 days of completion of repairs conducted in response to Item No. 3 above. Upon ADEQ s approval, the permittee shall implement the approved plan and schedule of corrective actions. 6. Within 30 days of completion of corrective actions, submit to ADEQ a written report as specified in Section (Corrective Actions) Discharge Limitations Violations Liner Failure, Containment Structure Failure, or Unexpected Loss of Fluid for a Reason Other than Overtopping In the event of liner failure, containment structure failure, or unexpected loss of fluid resulting in a discharge as defined by A.R.S (12) and as described in Section.3, the permittee shall take the following actions: 1. As soon as practicable, cease all discharges to the surface impoundment as necessary to prevent any further releases to the environment. 2) Within 24-hours of discovery, notify ADEQ Water Quality Compliance Section, Enforcement Unit. 3. Within five (5) days of discovery of a failure that resulted in a release to the subsurface, collect representative samples of the fluid remaining in the surface impoundment. Samples shall be analyzed for the parameters specified in Section 4, Table Within thirty (30) days of the incident, submit a copy of the analytical results to ADEQ Water Quality Compliance Section, Enforcement Unit. 4. Within fifteen (15) days of discovery, initiate an evaluation to determine the cause for the incident. Identify the circumstances that resulted in the failure and assess the condition of the surface impoundment and liner system. Implement corrective actions as necessary to resolve the problems identified in the evaluation. Initiate repairs to any failed liner, system, structure, or other component as needed to restore proper functioning of the surface impoundment. The permittee shall not resume discharging to the surface impoundment until repairs of any failed liner or structure are performed. Repair procedures, methods, and materials used to restore the system(s) to proper

14 p. 14 of 45 operating condition shall be described in the facility log/recordkeeping file and available for ADEQ review. 5. As soon as practicable, remove fluid remaining in the surface impoundment as necessary to prevent further releases to the subsurface and/or to perform repairs. Record in the facility log/recordkeeping file the amount of fluid removed, a description of the removal method, and other disposal arrangements. The facility log/recordkeeping file shall be maintained according to Section (Operation Inspection/Log/Recordkeeping File). 6. Within thirty (30) days of discovery of the incident, submit a report to ADEQ as specified in Section (Permit Violation and AL Status Reporting). Include a description of the actions performed in Subsections 1 through 5 listed above. Upon review of the report, ADEQ may request additional monitoring or remedial actions. 7. Within sixty (60) days of discovery, conduct an assessment of the impacts to the subsoil and/or groundwater resulting from the incident. If soil or groundwater is impacted such that it could cause or contribute to an exceedance of an AQL at the applicable point of compliance, submit to ADEQ, for approval, a corrective action plan to address such impacts, including identification of remedial actions and/or monitoring, and a schedule for completion of activities. At the direction of ADEQ, the permittee shall implement the approved plan. 8. Within thirty (30) days of completion of corrective actions, submit to ADEQ, a written report as specified in Section (Corrective Actions). Upon review of the report, ADEQ may amend the permit to require additional monitoring, increased frequency of monitoring, amendments to permit conditions, or other actions Overtopping of a Surface Impoundment If overtopping of fluid from a permitted surface impoundment occurs, and results in a discharge pursuant to A.R.S (12), the permittee shall: 1. As soon as practicable, cease all discharges to the surface impoundment to prevent any further releases to the environment. 2. Within 24-hours of discovery, notify ADEQ Water Quality Compliance Section, Enforcement Unit. 3. Within five (5) days, collect representative samples of the fluid contained in the surface impoundment. Samples shall be analyzed for the parameters specified in Section 4, Table Within thirty (30) days of the incident, submit a copy of the analytical results to ADEQ Water Quality Compliance Section, Enforcement Unit. 4. As soon as practicable, remove and properly dispose of excess water in the impoundment until the water level is restored at or below the appropriate freeboard as described in Table Record in the facility log, the amount of fluid removed, a description of the removal method, and the disposal arrangements. The facility log/recordkeeping file shall be maintained according to Section (Operation Inspection/Log/Recordkeeping File). 5. Within thirty (30) days of discovery, evaluate the cause of the overtopping and identify the circumstances that resulted in the incident. Implement corrective actions and adjust operational conditions as necessary to resolve the problems identified in the evaluation. Repair any systems as necessary to prevent future occurrences of overtopping. 6. Within thirty (30) days of discovery of overtopping, submit a report to ADEQ as specified in section (Permit Violation and AL Status Reporting). Include a description of the actions performed in Subsections 1 through 5 listed above. Upon review of the report, ADEQ may request additional monitoring or remedial actions. 7. Within sixty (60) days of discovery, and based on sampling in Subsection 3 above, conduct an assessment of the impacts to the subsoil and/or groundwater resulting from the incident. 8. If soil or groundwater is impacted such that it could cause or contribute to an exceedance of an AQL at the applicable point of compliance, submit to ADEQ for

15 p. 15 of 45 approval, a corrective action plan to address such impacts, including identification of remedial actions and/or monitoring, and a schedule for completion of activities. At the direction of ADEQ, the permittee shall implement the approved plan. 9. Within thirty (30) days of completion of corrective actions, submit to ADEQ, a written report as specified in Section (Corrective Actions). Upon review of the report, ADEQ may amend the permit to require additional monitoring, increased frequency of monitoring, amendments to permit conditions, or other actions Inflows of Unexpected Materials to a Surface Impoundment The types of materials that are expected to be placed in the permitted surface impoundments are specified in Section 2.3 (Discharge Limitations). If any unexpected materials flow to a permitted surface impoundment, the permittee shall: 1. As soon as practicable, cease all unexpected inflows to the surface impoundment(s). 2. Within 24-hours of discovery, notify ADEQ Water Quality Compliance Section, Enforcement Unit. 3. Within five (5) days of the incident, identify the source of the material and determine the cause for the inflow. Characterize the unexpected material and contents of the affected impoundment, and evaluate the volume and concentration of the material to determine if it is compatible with the surface impoundment liner. Based on the evaluation of the incident, repair any systems or equipment and/or adjust operations, as necessary to prevent future occurrences of inflows of unexpected materials. 4. Within thirty (30) days of an inflow of unexpected materials, submit a report to ADEQ as specified in Section (Permit Violation and AL Status Reporting). Include a description of the actions performed in Subsections 1 through 3 listed above. Upon review of the report, ADEQ may request additional monitoring or remedial actions. 5. Upon review of the report, ADEQ may amend the permit to require additional monitoring, increased frequency of monitoring, amendments to permit conditions, or other actions Aquifer Quality Limit (AQL) Violation 1. If an AQL set in Section 4.2, Tables or has been exceeded, the permittee may conduct verification sampling within five (5) days of becoming aware of an AQL exceedance. The permittee may use the results of another sample taken between the date of the last sampling event and the date of receiving the result as verification. 2. If verification sampling confirms that the AQL is violated for any parameter or if the permittee opts not to perform verification sampling, then the permittee shall increase the frequency of monitoring to monthly In addition, the permittee shall immediately initiate an evaluation for the cause of the violation, including inspection of all discharging units and all related pollution control devices, and review of any operational and maintenance practices that might have resulted in unexpected discharge. The permittee also shall submit a report according to Section 2.7.3, which includes a summary of the findings of the investigation, the cause of the violation, and actions taken to resolve the problem. A verified exceedance of an AQL will be considered a violation unless the permittee demonstrates within 30 days that the exceedance was not caused or contributed to by pollutants discharged from the facility. Unless the permittee has demonstrated that the exceedance was not caused or contributed to by pollutants discharged from the facility, the permittee shall consider and ADEQ may require corrective action that may include control of the source of discharge, cleanup of affected soil, surface water or groundwater, and mitigation of the impact of pollutants on existing uses of the aquifer. Corrective actions shall either be specifically identified in this permit, included in an ADEQ approved contingency plan, or separately approved according to Section