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Home My WebLink AboutDWQ-2024-0054091 APPENDIX D COMPLIANCE AND OPERATIONAL MONITORING PLAN GROUND WATER DISCHARGE PERMIT PERMIT NO. UGW350011 (June 2017) 1.0 INTRODUCTION This plan presents the sampling, analyses, and quality guidelines for the sampling of operational process discharges to the Tailings Impoundment. Sampling is being done to assure that the tailings inflows and interstitial water within the impoundment are consistent with the Best Available Technology (BAT) performance standards approved in the Tailings Impoundment Ground Water Discharge Permit No. UGW350011. This document satisfies the requirements of Part 1.E.2a and 2b of the permit. This monitoring plan complements the plan for Assessment of Acidification Potential (Appendix A) prepared to satisfy the requirements of Part I.H.1b of the permit. 2.0 MONITORING Tailings water to be monitored under this plan will characterize the interstitial waters (within the tailings), and seeps. Groundwater monitoring wells located around the perimeter of the impoundment will be monitored to observe trends in local groundwater and determine compliance. Table 1 contains the locations and frequency of required monitoring points described in this section. Tailings slurry solids will also be monitored. 2.1 Tailings Water Samples Tailings water samples will be collected from surface water sites and wells completed within the tailings footprint. 2.1.1 Surface Water Sites Surficial tailings water samples will be collected from the following locations: •Clarification Canal (sampling site CLC452) – This site will be sampledquarterly and was selected to show the quality of the tailings water as itreturns from the top of the Tailings Impoundment. This location is unaffected by other discharges to the clarification canal and represents nearly the entire return flow from the impoundment. Additionally, this site has a sampling history dating back to 1991 and is near the 001 UPDESOutfall. 2 • Toe Collection Ditch (sampling sites TLP1436, and TLP1469) - Will be sampled quarterly. Site TLP1436 is located in the toe collection ditch near the 007 UPDES Outfall and site TLP1469 is located adjacent to the former Gypstack. • Seeps (sampling site TLS1426) – This seep is located on the Tailings Impoundment embankment and has been sampled intermittently since 1985. Samples of this seep will be collected twice per year, once in the spring and in the late summer or early fall. The discovery of any new seeps within the tailings embankment should also be sampled and reported in the annual report. The locations of these sampling sites are shown on Figure 1. Samples will be collected using the procedures provided in Kennecott’s Standard Operating Procedures for Water Sampling. Protocols for handling samples and obtaining analyses will be as specified for ground water samples in the Ground Water Characterization and Monitoring Plan (GCMP). 2.1.2 Tailings Wells Tailings wells TLT887, TLT2452, TLT2575A, TLT2575B and NET2596 will be sampled semi-annually. These wells are constructed within the tailings and were selected to include wells located in various portions of the impoundment, both laterally and vertically. The locations of these wells are shown on Figure 1. Samples collected from these wells will be collected using sampling methods and protocols specified in the GCMP. New well construction will be done as specified in the GCMP. 2.1.3 Compliance Wells Compliance wells will be sampled according to the schedule listed Table 1. The compliance wells are located around the perimeter of the Tailings Impoundment complex and are completed in the aquifer system that ranges from Class II to Class IV. Additional monitoring and reporting requirements for non-compliance conditions are described in Part I, Section F of the permit. If the concentration of any pollutant exceeds the Compliance Limit in permit (Table 1) in any compliance monitoring well, Kennecott will initiate monthly sampling for the well(s) that have exceeded the Compliance Limit. Monthly sampling will continue for two months or until the compliance of the facility can be determined. Notification to the Executive secretary will be made in the corresponding semi-annual report. Compliance monitoring wells will be analyzed for those constituents listed in section 2.1.5 below. However, compliance will be determined based on the 3 following parameters: pH, arsenic, barium, cadmium, chromium, copper, lead, selenium, zinc, sulfate and TDS. 2.1.5 Analytes and Analytical Methods All surface and tailings well samples will be analyzed for pH, conductivity, temperature,Total Dissolved Solids (TDS), Total Suspended Solids (TSS), sulfate, chloride, alkalinity, sodium, potassium, magnesium, calcium, and dissolved for metals arsenic, barium, cadmium, chromium, copper, lead, selenium, silver, and zinc. Water levels will be measured immediately prior to collection of samples from the tailings wells. The methods used for analyses will be those specified in Table QAPP-2 of the Quality Assurance Project Plan for the Ground Water Characterization and Monitoring Plan (QAPP-GCMP). 2.1.6 Quality Assurance The quality assurance program for these samples will be as specified in the QAPP-GCMP. This requires a minimum of 20% duplicate, spike, spiked duplicate, equipment and trip blanks. The precision and accuracy objectives will be those specified in Table QAPP-1 of the QAPP-GCMP. 2.2 Solid Samples 2.2.1 Sample Collection Solid samples will be collected quarterly to semi-annually to characterize the metals content and metals solubility of materials discharged to the Tailings Impoundment. A total of five sites will be collected an analyzed: • West cyclone underflow tailings (TLP1485 - quarterly) • West cyclone overflow tailings (TLP1486 - semiannual) • East cyclone underflow tailings (TLP1487 - quarterly) • East cyclone overflow tailings (TLP1488 - semiannual) • Smelter slag/hydromet tailings (TLP2593 - semiannual) The Tailings North Tailings embankment is constructed of coarse underflow material from two cyclone stations (designated East and West Cyclones). The fine-grained overflow material is placed in the interior of the impoundment. The East and West Cyclone stations currently receives material only from the Copperton Concentrator. The Single Point discharge receives Copperton tailings, Power Plant fly ash and Smelter Slag/Hydromet 4 tailings. In the future, Smelter process waters may be directed to the West Cyclone station as well. 2.2.2 Analysis and Analytical Methods All of the solid samples will be analyzed for the following constituents: • Total Metals – As, Cd, Cr, Cu, Pb, Se and Zn, • SPLP – As, Cd, Cr, Cu, Pb, Se and Zn. Total metals analysis will be conducted according to EPA SW846 Method 6010 or 6020. SPLP analysis will be conducted according to EPA SW846 Method 1312. 2.2.3 Quality Assurance The quality assurance program for these samples will require a minimum rate of 20% for duplicate, spike, spiked duplicate, and blank samples. The precision objectives will require duplicate samples to have Relative Percent Differences (RPD) of less than 25%. Accuracy objective will be spike recoveries between 65% and 135%. Blank samples will show no concentrations above the detection limit. The completeness goal is 100%. 5 3.0 REPORTING Results of the water samples and the solid sampling will be reported in the annual monitoring report required and described in Appendix A. 6 TABLE 1 - SAMPLE SCHEDULE AND WELL CONSTRUCTION DETAILS DESCRIPTION SAMPLE IDENTIFICATION SAMPLE FREQUENCY NORTHING1 EASTING1 ELEVATION GROUND (ft amsl)2 ELEVATION MARK (ft amsl)2 CASING DIAMETER (ft) SCREEN TOP (ft) SCREEN BOTTOM (ft) WELL DEPTH (ft) Surface Water CLC452 quarterly 7430598 1478952 NA NA NA NA NA NA Toe Ditch TLP1436 quarterly 7449537 1472811 NA NA NA NA NA NA TLP1469 quarterly 7443912 1456331 NA NA NA NA NA NA Seeps TLS1426 semiannual (if flowing) 7430584 1469199 NA NA NA NA NA NA Tailings Wells NET2596 semiannual 7432501 1475907 4382.23 0.00 0.208 123.0 133.0 135.00 TLT887 semiannual 7437118 1456907 0.00 NA NA NA NA NA TLT2575B semiannual 7435211 1476230 0.00 0.00 0.208 233.0 245.0 247.00 TLT2575A semiannual 7435232 1476230 0.00 4385.20 0.333 171.0 181.0 177.15 TLT2452 semiannual 7438543 1478307 NA 0.00 0.000 19.0 0.0 201.00 Compliance Wells NEL532A semiannual 7434362 1478810 4225.52 4226.87 0.130 11.0 16.0 19.43 NEL532B semiannual 7433998 1478790 4226.53 4226.48 0.130 38.0 43.0 46.00 NEL536A annual 7431812 1478851 4231.35 4233.68 0.130 10.3 15.3 17.55 NEL536B annual 7431448 1478830 4231.21 4232.66 0.130 34.7 39.7 41.60 NED604A semiannual 7429873 1471526 4251.69 4254.76 0.170 15.0 25.0 26.42 NED604B semiannual 7429335 1471523 4251.89 4254.74 0.170 65.0 80.0 79.95 NET646A semiannual 7447372 1458412 4212.93 4215.33 0.170 5.0 15.0 17.93 NET646B semiannual 7447038 1458153 4212.90 4215.37 0.170 39.6 49.6 51.73 NEM1387 semiannual 7430720 1472930 4245.02 4247.76 0.208 10.0 20.0 21.00 NET1380A semiannual 7437100 1454702 4226.14 4227.98 0.208 13.5 23.5 24.50 NET1380B annual 7437095 1454707 4226.32 4228.09 0.208 54.0 64.0 65.00 NET1381A semiannual 7443041 1479775 4220.39 4222.31 0.208 25.0 35.0 36.00 NET1381B semiannual 7443036 1479750 4220.21 4222.21 0.208 44.0 54.0 55.00 NEL1382A semiannual 7437371 1480785 4224.20 4225.81 0.208 10.0 20.0 21.00 NEL1382B semiannual 7437371 1480785 4224.27 4226.61 0.208 29.0 39.0 40.00 NEL1382C semiannual 7437371 1480785 4224.42 4226.51 0.208 88.0 98.0 100.00 NET1383A semiannual 7449638 1473603 4214.85 4217.45 0.208 14.0 24.0 25.00 NET1383B semiannual 7449659 1474064 4215.49 4217.55 0.208 34.0 44.0 45.00 NET1384A semiannual 7449093 1466595 4215.93 4217.94 0.208 13.0 23.0 25.00 7 TABLE 1 - SAMPLE SCHEDULE AND WELL CONSTRUCTION DETAILS (cont.) DESCRIPTION SAMPLE IDENTIFICATION SAMPLE FREQUENCY NORTHING1 EASTING1 ELEVATION GROUND (ft amsl)2 ELEVATION MARK (ft amsl)2 CASING DIAMETER (ft) SCREEN TOP (ft) SCREEN BOTTOM (ft) WELL DEPTH (ft) Compliance Wells NET1385A semiannual 7446677 1477638 4215.65 4217.94 0.208 14.5 24.5 25.00 NET1385B semiannual 7446252 1478003 4215.70 4218.16 0.208 60.0 70.0 71.00 NET1386A annual 7441038 1454228 4216.96 4218.67 0.208 29.0 39.0 40.00 NET1386B annual 7440466 1453934 4217.05 4218.84 0.208 61.0 71.0 72.00 NET1393A semiannual 7443665 1455650 4218.86 4220.68 0.208 29.0 39.0 40.00 NET1393B semiannual 7443665 1455650 4219.07 4220.98 0.208 58.0 68.0 70.00 NET1490 semiannual 7432489 1459150 4333.84 4334.99 0.208 105.4 124.9 130.00 NET1491 semiannual 7432962 1459180 4340.87 4343.67 0.208 125.8 145.0 149.93 NET1492 semiannual 7433416 1459256 4346.84 4244.32 0.208 107.4 127.2 128.98 1. Northing and Easting Coordinates in State Plane NAD83 2. Elevations use NGVD29 3. All samples will be analyzed for pH, conductivity, temperature, TDS TSS, sulfate, chloride, alkalinity, sodium, potassium, magnesium, calcium, arsenic, barium cadmium, chromium, copper, lead selenium, silver and zinc.