Document dQeemNqemz2o228ojoXypmqY0

Sisecam Wyoming, LLC, Big Island Mine and Refinery- Trona Sampling Inspections - Sweetwater County, Wyoming On-Site Partial Compliance Evaluations (PCE) Inspection Dates: Inspection Report Date: Inspection Report Prepared By: Inspection Report Reviewed By: Inspectors: Company Representatives: Mailing Address: Facilities County/State Location: EPA Region: Specific Facility Information: 3/28/2023 9/20/2023 Colin LeCortz, US EPA Scott Patefield, Manager, US EPA Region 8, Enforcement and Compliance Assurance Division, Air and Toxics Enforcement Branch SCOTT PATEFIELD Date: 2023.09.20 16:02:25 -06'00' Digitally signed by SCOTT PATEFIELD x Katelyn Bergl (US EPA) x Travis Guthrie (WYDEQ) x Tyler Schiltz x Hilary M. Huckfeldt x Mike McGrady x Craig Rood x Paul Larson Note: Other facility representatives joined during additional times during the sampling and inspection. P.O. Box 514, Green River, Wyoming 82935 Sweetwater County/ Wyoming Region 8 SIC: 1474 NAICS Code: 212391 Inspection Information United States Environmental Protection Agency (EPA) conducted sampling inspections and gas chromatography- mass spectroscopy (GCMS) at the Sisecam Wyoming, LLC (Sisecam), Big Island Mine and Refinery (the facility) in southwest Wyoming as part of a regional effort to characterize volatile organic compound (VOC) emissions from trona mining and its processing into soda ash. The objective of the sampling was to evaluate the VOC and total petroleum hydrocarbon (TPH) content of the trona ore and evaluate potential emissions from the calciners that operate at the facility. The calciners operate at approximately 2,000 degrees Fahrenheit (F) according to site personnel and seen by EPA inspectors during process reviews. At this temperature there is a potential to release entrained and form VOC's from the total petroleum hydrocarbons that may be present in the trona ore. The Title V operating permit (Permit# P0024380) contains no VOC controls for any processing unit at the facility. No federal requirements apply for calciners at trona facilities to control VOC emissions. The VOC potential to emit reported in the December 2016 BACT analysis was 101.6 tpy from Unit 6, and 208.5 tpy from Unit 7. Page 1 of 19 EPA inspectors collected 10 samples during the on-site inspection at Big Island Mine and Refinery. One sample labeled FB/TB in Table 1 below, was a trip blank that contained sodium sesquicarbonate, a clean, manufactured trona analogue. The trip blank was part of the quality assurance project plan. Two of the samples were collected from process locations after the calciner (emission unit: Unit 6). Samples were collected from processes before and after the calciner unit to reflect the broad spatial operations at the facility. Locations included samples at the following locations: mine face, conveyor belt post-mine face, trona crushers above ground, precalciner conveyor belt, post-calciner and dryer of Unit 6, and the post-calciner insolubles. The sampling locations are shown in Table 1 for the facility inspection on March 28, 2023. The sampling was conducted by EPA inspectors Colin LeCortz and Katelyn Bergl, TPH sample analysis was conducted by Dr. Richard Helmich at EPA's National Enforcement Investigations Center (NEIC) laboratory in Lakewood, Colorado. Date and Time (MDT) 3/9/2023, 16:00 3/28/2023, 10:24 3/28/2023, 10:26 3/28/2023, 10:26 3/28/2023, 10:28 3/28/2023, 12:48 3/28/2023, 13:21 3/28/2023, 13:23 3/28/2023, 13:24 3/28/2023, 13:44 3/28/2023, 13:58 Station Number FB/TB S01a S01b S01c S02 S03 S04a S04b S04c S05 S06 Table 1 - Sample Locations at the Facility Station Location Field Blank/Trip Blank Mine Face (Triplicate) Mine Face (Triplicate) Mine Face (Triplicate) Conveyor belt, post mine face Crusher, above ground Unit 6 pre-calciner Unit 6 pre-calciner Unit 6 pre-calciner Post-calciner Unit 6 Post-calciner, insolubles Analysis TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) TPH Analysis (GCMS) Sample Tag Number NE46645 NE46621 NE46622 NE46630 NE46633 NE46631 NE46629 NE46632 NE46642 NE46643 NE46634 Remarks Prepared by ROH 3/8/23 Mine, pre-calciner Mine, pre-calciner Mine, pre-calciner Conveyor belt Crusher, above ground Unit 6 Calciner inlet Unit 6 Calciner inlet Unit 6 Calciner inlet Post-calciner Post-calciner insolubles The inspection team adhered to the following approach to collect trona samples: 1) On 3/28/2023, at approximately 8:45 am, the EPA met with Travis Guthrie, WYDEQ and multiple Sisecam representatives to discuss inspection scope, and safety. Sisecam representatives confirmed that sampling trona ore and refined product was permitted to be conducted by EPA inspectors. 2) EPA inspectors chose sampling locations along the entire facility process from the mine face to the finished product. 3) When a sampling location was selected, EPA inspectors used new, sealed jars and scoops to collect the samples. Scoops were discarded after use to eliminate sample cross contamination. Sample jars were new, unused and had a certificate of cleanliness. 4) Only EPA inspectors collected each sample and maintained the samples in their possession at all times. Page 2 of 19 5) A NEIC Chain of Custody Record form was used to document the samples collected. See copy at Appendix A. 6) Each sample collected had a NEIC tag filled out and affixed to each jar with information that matched the Chain of Custody Record. 7) The lidded sample jars and sample tag were then placed into a tamper-evident bags and sealed. 8) At the end of the inspection, the jars were placed on ice in a locked cooler. The locked cooler was driven to NEIC on 3/29/23 and released to Richard Helmich at NEIC. Ice was present in the cooler was upon release to NEIC, and the cooler was placed in a walk-in refrigerator at 4 degrees Celsius (C) for storage. 9) Richard Helmich verified each bag's seal was maintained upon sample receipt on 3/30/2023. 10) The summary of GCMS analysis results are in Table 2. EPA inspectors made the following notes of Sisecam representatives who took co-located samples: 1) Sisecam representatives retrieved samples in bags that were not tamperproof. 2) Sisecam representatives used their bare hands to transfer samples from different locations into their sample bags. GCMS Testing Information The samples taken from the facility were tested at the National Enforcement Investigations Center laboratory, in Lakewood, Colorado. The analysis results are summarized in Table 2. NEIC prepared a Quality Assurance Project Plan (QAPP) that detailed the TPH extraction method, GCMS analysis, and results to be reported that was approved by NEIC on July 10, 2023 (See Appendix B). NEIC issued a report detailing the test methods and TPH content from the samples (See Appendix C). The results covered TPH in a carbon chain range of approximately C6 through C32+. The samples appeared to contain primarily diesel and heavier hydrocarbon compounds, which is outside of the VOC range. Field Notes EPA and WYDEQ inspectors arrived at the facility at 8:45 am where a safety video was reviewed. Facility representatives Tyler Schiltz and Hilary M. Huckfeldt met the inspectors after the safety video where the inspection and sampling that was planned was discussed. Facility representatives gave verbal permissions for sample to be collected along the process line at the facility. WYDEQ inspector Travis Guthrie was onsite to also conduct a full compliance evaluation of the facility, which occurred in conjunction with this EPA's sampling project. The inspectors then proceeded to receive mine-safety personal protective equipment and enter the elevator into the mine at approximately 9:45 am. The mine is located approximately 850 feet below the surface, and uses "long bed" room and pillar mining to extract trona ore from underground. Inspectors were informed that this facility is the shallowest trona mine, and most others in Sweetwater county, WY operate mines greater than twice the depth of the Sisecam facility. The mine, which commenced operations in 1962, operates 365 days per year, 24 hours in the day. It has an approximate maximum throughput of 16,000 tons of trona ore per day, which is processed into approximately 8,000 tons of soda ash per day. In 2022, the facility processed 4.37 million tons of trona ore into 2.7 million tons of soda ash, according to facility records reviewed onsite. Page 3 of 19 Once below ground in the mine, the inspectors and facility representatives loaded into vehicles to travel to the mine face; where mining was actively occurring. The facility has 4 active mine faces. The simplified underground process is as follows: Each mechanical miner can remove 30 tons per minute of trona ore into carts to transmit the ore to a conveyor belt. The conveyor belt routes the trona ore to elevators that lift the trona ore to the surface for further processing. The inspectors took the first samples at the mine face. Three samples were collected from the same area (within 5 feet of each other sample), called a triplicate sample. The mine face was noted as station number S01. The triplicate samples were collected at 10:24 am, 10:26 am and 10:28 am, respectively. Those stations were denoted as S01a, S01b, and S01c to uniquely identify the individual triplicate samples. The next samples were taken approximately 200 yards away from the mine face on the conveyor belt that leads to the elevators. This underground location along the conveyor belt in the mine was noted as station number S02. Sample S02 was collected at 10:56 am. The inspectors and facility representatives traveled back to the elevator and went to a meeting room at the facility to learn additional information about the above ground process units. The above ground trona processing consists of ore is brought up from the mine in the elevator, the ore enters a crusher, the crushed trona ore then is conveyed to the calciners where it is heated to 2,000 F to drive off impurities and to convert the trona ore's bicarbonate component into sodium carbonate. The ore is then disolved in water where the insolubles drop out. Water usage at the facility is about 800 million gallons per year, which includes evaporation through dryer stacks. The insoluble tailings are routed to an evaporation pond and then returned to the mine over time. The aqueous sodium carbonate solution (commonly referred to as liquor) is then heated in a dryer where soda ash crystals form and can be routed to sales. Calciner Unit 6 and Unit 7 have a maximum processing capacity of about 240 ton/hr and 380 tons/hr of trona ore, respectively. Calciner Unit 6 is a process unit that includes both the calciner and dryer all in one process, while calciner Unit 7 is just a calciner. Samples were only taken from Unit 6 on 3/28/2023 due to time limitations caused by the large size of the facility and time required to travel between each process step. The time limitation prohibited collecting additional sampling during the inspection; however, each calciner receives trona from the same mine. Therefore samples from Unit 7 would not be expected to yield significantly different results compared those collected at Unit 6. A live view of the calciner temperatures indicated that Unit 6 was operating at 2261F and Unit 7 was operating at 2284F. The only emissions controls in use at the calciners were electrostatic precipitators to control particulate matter. At 12:48 pm, sample S03 was collected at the crusher above ground after the ore was lifted via elevator above ground. A second set of triplicate samples, S04a, S04b and S04c, was collected on the conveyor belt leading into Unit 6 calciner. These samples were taken at 1:21 pm, 1:23 pm and 1:24 pm directly from the moving conveyor belt. At 1:44 pm a sample of finished soda ash product, S05, was collected from Unit 6 post calciner and drier. At 1:58 pm, sample S06 was collected from the post calciner insoluble outlet line. Sample S06 was wet insoluble solids that settle out of the liquor when the trona ore is dissolved. EPA and WYDEQ inspectors then drove around the facility grounds to review sources of potential particulate matter emissions. The facility walkthrough ended at 2:49 pm. WYDEQ inspector Travis Guthrie then discussed permit terms related to his full compliance evaluation that was completed in conjunction with EPA's sampling project. Page 4 of 19 Both EPA and WYDEQ inspectors left the facility at 3:58 pm after discussion of the permit terms and the full compliance evaluation. Additional sources of emissions: DECA plant: Sisecam operates the DECA plant which recovers sodium carbonate decahydrate from the evaporation ponds from earlier production. Liquor entrained with previously generated insoluble solids is removed from the evaporation ponds and reprocessed at the DECA plant. The DECA plant processes 876,000 tons of sodium carbonate decahydrate into 271,700 tons of soda ash. EPA inspectors did not assess or inspect this process unit. ENG007: Sisecam operates a Solar Titan 250 Turbine/Heat Recovery Steam Generator for on-site power. EPA inspectors did not assess or inspect this unit. Seeking Sisecam Review and Input The EPA sent a request for additional information for further compliance evaluation on 4/19/2022 and Sisecam responded on 4/25/2023. The following information was requested, and Sisecam responses are italicized: x Provide the calciner emission calculations for Unit 6 and Unit 7 used to determine BACT economic feasibility. The most recent BACT evaluation completed for the Big Island Unit 6 and Unit 7 calciners was prepared as part of the Production Improvement Projects PSD application, submitted through IMPACT (A0003723) in December 2016. The Calciner emission calculations were included as Appendix C in that application. A portion of Appendix C is in the OneDrive folder, and the complete appendix is also available in OpenAir for EPA's reference. The Calciner emissions were used in the BACT control cost calculations for the economic feasibility evaluation, Appendix D, Attachment A, Tables A1-3.1 through 3.7 and Tables A2-3.1 through 3.7. Those portions of Appendix D is in the OneDrive folder, and the entire appendix is available in OpenAir for EPA's reference. Note: Documents discussed above were provided by Sisecam as an email attachment. x Does trona ore come in direct contact with the calciner burner or is it shielded? If it is shielded what is the interface temperature? There is no shield - the heat from the flame goes into the calciner and comes in direct contact with the ore in both calciners. x Would the calciner exhaust include any potential emissions from the trona ore exhaust? Or does the calciner exhaust separately from the process stream/trona ore? Please provide an internal schematic or photos of each calciner if those are more helpful or easier to show. The gas exhaust and trona ore exhaust are part of the same exhaust stream that goes through the ESP, and exits through the calciner stack to the atmosphere. P&IDs showing the gas flow from the burner into the kiln are provided in the OneDrive folder for Unit 6 and Unit 7 calciners. Note: Documents discussed above were provided by Sisecam as an email attachment. Page 5 of 19 x Have either Unit 6 or Unit 7 calciners been modified since 2018? The lifters in the Unit 7 calciner have been replaced, but no modifications have occurred on the Unit 6 calciner since 2018. x Provide the most recent fuel gas analyses available used as feed stock for each calciner. Please find the March 1st gas analysis in the OneDrive folder. Note: Documents discussed above were provided by Sisecam as an email attachment. x Provide the manufacturer recommended maintenance and servicing for each calciner. The manufacturer recommends daily, weekly, monthly, and annual preventative maintenance work and inspections to monitor the ongoing condition of the calciner. The frequency of the preventative maintenance work and inspections are specific to each calciner component. Lubrication checks are recommended on a daily basis and weekly basis. Inspections to the overall drive train, calciner shell, and insulation system are recommended weekly and monthly. Internal inspections are recommended annually to assess the internal condition of the shell and the product lifters. External inspections are also recommended annually on the rotating drive components. Both Unit 6 and Unit 7 calciners are very similar pieces of equipment. As such, the maintenance recommendations are analogous for both units. x Provide results of any stack testing conducted on the calciners since January 1, 2018 and now, if possible. Annual stack tests on Unit 6 (6ES10) and Unit 7 (7ES10) calciners have occurred since 2018, which can be found in the OneDrive folder. Note: Documents discussed above were provided by Sisecam as an email attachment. Page 6 of 19 Table 2 - Sampling Results Station Number FB/TB S01a S01b S01c S02 S03 S04a S04b S04c S05 S06 Sample Tag Number NE46645 NE46621 NE46622 NE46630 NE46633 NE46631 NE46629 NE46632 NE46642 NE46643 NE46634 Results (weight%) 0.0007 0.0334 0.0307 0.0075 0.0081 0.0060 0.0142 0.0053 0.0100 0.0006 0.0381 Results (mg/kg) 7 334 307 75 81 60 142 53 100 6 381 TPH per year (tons)* NA 1950 1790 438 473 350 829 310 584 17.5 1110 *Extrapolated using the following equation for S01a through S04c: 334 0.000002205 16,000 365 1: = 1,950 0.001102 2000 *Extrapolated using the following equation for S05 and S06: 381 0.000002205 8,000 365 6: = 1110 0.001102 2000 Page 7 of 19 Appendix A - NEIC Chain of Custody Record Page 8 of 19 Appendix B - NEIC Quality Assurance Project Plant Page 9 of 19 Page 10 of 19 Page 11 of 19 Page 12 of 19 Page 13 of 19 Page 14 of 19 Appendix C- NEIC TPH Report Page 15 of 19 Page 16 of 19 Page 17 of 19 Page 18 of 19 Page 19 of 19