{"data":{"schemaVersion":"realm.mine-profile.v1","generatedAt":"2026-10-13T11:26:59.401Z","identity":{"mine_id":"2104045","name":"K400","status":"Intermittent","status_date":"2023-03-09","mine_type":"Surface","coal_metal":"M","commodity":"Sand, Common","state":"MN","county":"St Louis","nearest_town":"Duluth","operator_id":"L16472","operator_name":"Mathy Const. Co. DBA Northland Constrs. of Duluth","controller_id":"M00893","controller_name":"Mathy Construction Company","district":"M4","office":"Duluth MN Field Office","employees":3,"latitude":46.861667,"longitude":-92.153333},"coverage":{"contributingSources":9,"registeredSources":20,"sourceRows":37},"relationships":{"schemaVersion":"realm.temporal-relationships.v1","temporalSemantics":{"validTime":{"granularity":"date","bounds":"inclusive","nullStart":"start date not published in the upstream history row","nullEnd":"open-ended in the upstream history row; not independent proof of present control"},"transactionTime":{"observedAt":"2026-10-13T11:19:05.459773+00:00","meaning":"time the checksum-addressed MDRS artifacts were observed by the PostgreSQL ingestion"},"derivation":{"controllerControlsOperator":"intersection of controller and operator valid-time intervals evidenced through this mine","currentIdentity":"current controller and operator are asserted only by the MDRS Mines snapshot"}},"current":{"mine":{"type":"mine","id":"2104045","name":"K400"},"operator":{"type":"operator","id":"L16472","name":"Mathy Const. Co. DBA Northland Constrs. of Duluth"},"controller":{"type":"controller","id":"M00893","name":"Mathy Construction Company"},"source":{"datasetId":"msha-mines","observedAt":"2026-10-13T11:19:05.459773+00:00"}},"edges":[{"type":"controller_controls_mine","subject":{"type":"controller","id":"M00893","name":"Mathy Construction Company"},"object":{"type":"mine","id":"2104045","name":"K400"},"validFrom":"1950-01-01","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-13T11:19:05.459773+00:00","recordKey":"2104045|M00893|1950-01-01|"}},{"type":"operator_operates_mine","subject":{"type":"operator","id":"0191433","name":"Northland Constructors of Duluth, Inc."},"object":{"type":"mine","id":"2104045","name":"K400"},"validFrom":"2023-02-23","validTo":"2023-12-17","current":false,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-13T11:19:05.459773+00:00","recordKey":"2104045|0191433|2023-02-23|2023-12-17"}},{"type":"controller_controls_mine","subject":{"type":"controller","id":"0179622","name":"API Group Inc"},"object":{"type":"mine","id":"2104045","name":"K400"},"validFrom":"2023-02-23","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-13T11:19:05.459773+00:00","recordKey":"2104045|0179622|2023-02-23|"}},{"type":"controller_controls_operator","subject":{"type":"controller","id":"0179622","name":"API Group Inc"},"object":{"type":"operator","id":"0191433","name":"Northland Constructors of Duluth, Inc."},"validFrom":"2023-02-23","validTo":"2023-12-17","current":false,"derived":true,"evidenceMineId":"2104045","intervalAnomaly":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-13T11:19:05.459773+00:00","recordKey":"2104045|0191433|2023-02-23|0179622|2023-02-23|38407"}},{"type":"operator_operates_mine","subject":{"type":"operator","id":"L16472","name":"Northland Constrs. of Duluth"},"object":{"type":"mine","id":"2104045","name":"K400"},"validFrom":"2023-12-18","validTo":null,"current":true,"derived":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-13T11:19:05.459773+00:00","recordKey":"2104045|L16472|2023-12-18|"}},{"type":"controller_controls_operator","subject":{"type":"controller","id":"M00893","name":"Mathy Construction Company"},"object":{"type":"operator","id":"L16472","name":"Northland Constrs. of Duluth"},"validFrom":"2023-12-18","validTo":null,"current":true,"derived":true,"evidenceMineId":"2104045","intervalAnomaly":false,"source":{"datasetId":"msha-controller-operator-history","observedAt":"2026-10-13T11:19:05.459773+00:00","recordKey":"2104045|L16472|2023-12-18|M00893|1950-01-01|115702"}}],"coverage":{"historyRecords":2,"edgeCount":6,"intervalAnomalies":0,"sourceDatasetId":"msha-controller-operator-history"}},"sources":[{"id":"msha-addresses","name":"Addresses of Record","domains":["identity","logistics"],"products":["entity resolution","address history","facility geocoding"],"rowCount":1,"firstDate":"2023-03-09","lastDate":"2023-03-09","metrics":{},"periods":{},"recentRecords":[]},{"id":"msha-assessed-violations","name":"Assessed Violations","domains":["compliance","legal"],"products":["penalty lifecycle","paid and outstanding amounts","assessment aging"],"rowCount":2,"firstDate":"2023-06-07","lastDate":"2023-07-05","metrics":{"ss":1,"delinquent":2,"recentRows":2,"paidPenalty":286,"proposedPenalty":286,"currentAssessment":286},"periods":{},"recentRecords":[{"SOURCE_ROW_NUMBER":"2699620","VIOLATION_NO":"9625399","ISSUE_DT":"07/05/2023","CFR_STANDARD_CD":"56.5001(a)/56.5005","SIG_SUB_IND":"Y","CITATION_TYPE_CD":"Citation","PROPOSED_PENALTY_AMT":"143.00","CURRENT_ASSESSMENT_AMT":"143.00","ASSESS_CASE_STATUS_CD":"Closed","sourceDate":"2023-07-05"},{"SOURCE_ROW_NUMBER":"2699619","VIOLATION_NO":"9625385","ISSUE_DT":"06/07/2023","CFR_STANDARD_CD":"56.13015(a)","SIG_SUB_IND":"N","CITATION_TYPE_CD":"Citation","PROPOSED_PENALTY_AMT":"143.00","CURRENT_ASSESSMENT_AMT":"143.00","ASSESS_CASE_STATUS_CD":"Closed","sourceDate":"2023-06-07"}]},{"id":"msha-controller-operator-history","name":"Controller and Operator History","domains":["identity","compliance"],"products":["historical ownership attribution","operator transitions","valid-time joins"],"rowCount":2,"firstDate":"2023-02-23","lastDate":"2023-12-18","metrics":{"recentRows":2,"currentOperatorTenures":1,"completedOperatorTenures":1},"periods":{},"recentRecords":[]},{"id":"msha-inspections","name":"Inspections","domains":["safety","compliance"],"products":["inspection mix","on-site hours","event context","citation rate denominator"],"rowCount":7,"firstDate":"2023-06-07","lastDate":"2026-07-15","metrics":{"inspectors":7,"recentRows":7,"onSiteHours":37.25,"inspectionHours":68.75,"inspectionSamples":0},"periods":{},"recentRecords":[{"SOURCE_ROW_NUMBER":"131116","EVENT_NO":"F00A464","INSPECTION_BEGIN_DT":"07/15/2026","INSPECTION_END_DT":"07/15/2026","ACTIVITY_CODE":"E01","ACTIVITY":"Regular Safety and Health Inspection","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":"7","SUM_TOTAL_ON_SITE_HOURS":"1.75","sourceDate":"2026-07-15"},{"SOURCE_ROW_NUMBER":"657084","EVENT_NO":"F0242F9","INSPECTION_BEGIN_DT":"07/15/2025","INSPECTION_END_DT":"07/15/2025","ACTIVITY_CODE":"E28","ACTIVITY":"Mine Idle Activity","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":".5","SUM_TOTAL_ON_SITE_HOURS":".5","sourceDate":"2025-07-15"},{"SOURCE_ROW_NUMBER":"465542","EVENT_NO":"F016C84","INSPECTION_BEGIN_DT":"09/05/2024","INSPECTION_END_DT":"09/05/2024","ACTIVITY_CODE":"E28","ACTIVITY":"Mine Idle Activity","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":"7.25","SUM_TOTAL_ON_SITE_HOURS":"3.25","sourceDate":"2024-09-05"},{"SOURCE_ROW_NUMBER":"342205","EVENT_NO":"F011CE2","INSPECTION_BEGIN_DT":"07/31/2024","INSPECTION_END_DT":"07/31/2024","ACTIVITY_CODE":"E28","ACTIVITY":"Mine Idle Activity","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":"5.25","SUM_TOTAL_ON_SITE_HOURS":"1","sourceDate":"2024-07-31"},{"SOURCE_ROW_NUMBER":"660800","EVENT_NO":"6907192","INSPECTION_BEGIN_DT":"07/06/2023","INSPECTION_END_DT":"07/06/2023","ACTIVITY_CODE":"E15","ACTIVITY":"Compliance Follow-up Inspection","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":"18.5","SUM_TOTAL_ON_SITE_HOURS":"13","sourceDate":"2023-07-06"},{"SOURCE_ROW_NUMBER":"670131","EVENT_NO":"6907182","INSPECTION_BEGIN_DT":"06/20/2023","INSPECTION_END_DT":"06/20/2023","ACTIVITY_CODE":"E15","ACTIVITY":"Compliance Follow-up Inspection","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":"8.75","SUM_TOTAL_ON_SITE_HOURS":"2","sourceDate":"2023-06-20"},{"SOURCE_ROW_NUMBER":"268660","EVENT_NO":"6907174","INSPECTION_BEGIN_DT":"06/07/2023","INSPECTION_END_DT":"06/08/2023","ACTIVITY_CODE":"E01","ACTIVITY":"Regular Safety and Health Inspection","NBR_INSPECTOR":"1","SUM_TOTAL_INSP_HOURS":"21.5","SUM_TOTAL_ON_SITE_HOURS":"15.75","sourceDate":"2023-06-07"}]},{"id":"msha-mine-production-quarterly","name":"Mine Employment and Production — Quarterly","domains":["production","safety","compliance"],"products":["production trend","employee hours","rate denominators","seasonality"],"rowCount":14,"firstDate":null,"lastDate":null,"metrics":{},"periods":{"2026-Q2":{"hours":1,"employees":1,"production":0},"2026-Q1":{"hours":1,"employees":1,"production":0},"2025-Q4":{"hours":1,"employees":1,"production":0},"2025-Q3":{"hours":1,"employees":1,"production":0},"2025-Q2":{"hours":182,"employees":2,"production":0},"2025-Q1":{"hours":1,"employees":1,"production":0},"2024-Q4":{"hours":1,"employees":1,"production":0},"2024-Q3":{"hours":1,"employees":1,"production":0},"2024-Q2":{"hours":1,"employees":1,"production":0},"2024-Q1":{"hours":0,"employees":0,"production":0},"2023-Q4":{"hours":880,"employees":2,"production":0},"2023-Q3":{"hours":2533,"employees":4,"production":0}},"recentRecords":[]},{"id":"msha-mine-production-yearly","name":"Mine Employment and Production — Yearly","domains":["production","safety","compliance"],"products":["annual trend","backfill","quarterly reconciliation"],"rowCount":4,"firstDate":null,"lastDate":null,"metrics":{},"periods":{"2023":{"hours":4900,"employees":3,"production":0},"2024":{"hours":3,"employees":1,"production":0},"2025":{"hours":185,"employees":1,"production":0},"2026":{"hours":2,"employees":1,"production":0}},"recentRecords":[]},{"id":"msha-mines","name":"Mines","domains":["identity","production","logistics"],"products":["mine identity","status","commodity","location","operator and controller"],"rowCount":1,"firstDate":null,"lastDate":null,"metrics":{},"periods":{},"recentRecords":[]},{"id":"msha-personal-health-samples","name":"Metal and Nonmetal Personal Health Samples","domains":["health","safety"],"products":["personal exposure trend","occupation patterns","analyte coverage"],"rowCount":4,"firstDate":"2023-06-08","lastDate":"2023-07-06","metrics":{"recentRows":4,"actionTaken":4,"maxExposureRatio":1.87,"overExposureLimit":1,"exposureRatioTotal":2.75},"periods":{},"recentRecords":[{"SOURCE_ROW_NUMBER":"279206","EVENT_NO":"6907192","SAMPLE_NO":"000000202302921100","SAMPLE_DATE":"07/06/2023","CONTAMINANT_DESC":"Respirable dust, <.1mg","CONCENTRATION":"0000.00","EXPOSURE_LIMIT":"0000.00","C_OVER_E":"00.00","JOB_CD_DESC":"Crusher Oper/Worker","ACTION_TAKEN_DESC":"NO ACTION","sourceDate":"2023-07-06"},{"SOURCE_ROW_NUMBER":"279205","EVENT_NO":"6907192","SAMPLE_NO":"000000202302921000","SAMPLE_DATE":"07/06/2023","CONTAMINANT_DESC":"Respirable dust, <.1mg","CONCENTRATION":"0000.00","EXPOSURE_LIMIT":"0000.00","C_OVER_E":"00.00","JOB_CD_DESC":"Front-end Loader Operator","ACTION_TAKEN_DESC":"NO ACTION","sourceDate":"2023-07-06"},{"SOURCE_ROW_NUMBER":"270748","EVENT_NO":"6907174","SAMPLE_NO":"000000202302529000","SAMPLE_DATE":"06/08/2023","CONTAMINANT_DESC":"Quartz, respirable, >1% Qtz","CONCENTRATION":"0001.61","EXPOSURE_LIMIT":"0000.86","C_OVER_E":"01.87","JOB_CD_DESC":"Front-end Loader Operator","ACTION_TAKEN_DESC":"CITATION/ORDER ISSUED","sourceDate":"2023-06-08"},{"SOURCE_ROW_NUMBER":"270747","EVENT_NO":"6907174","SAMPLE_NO":"000000202302528900","SAMPLE_DATE":"06/08/2023","CONTAMINANT_DESC":"Quartz, respirable, >1% Qtz","CONCENTRATION":"0000.63","EXPOSURE_LIMIT":"0000.72","C_OVER_E":"00.88","JOB_CD_DESC":"Crusher Oper/Worker","ACTION_TAKEN_DESC":"NO ACTION","sourceDate":"2023-06-08"}]},{"id":"msha-violations","name":"Violations","domains":["compliance","safety","legal"],"products":["citation and order record","condition text","Title 30 linkage","abatement patterns"],"rowCount":2,"firstDate":"2023-06-07","lastDate":"2023-07-05","metrics":{"ss":1,"amountDue":286,"contested":0,"amountPaid":286,"recentRows":2,"section104d":0,"unterminated":0,"proposedPenalty":286},"periods":{},"recentRecords":[{"SOURCE_ROW_NUMBER":"1387919","VIOLATION_NO":"9625399","VIOLATION_ISSUE_DT":"07/05/2023","SIG_SUB":"Y","PART_SECTION":"56.5001(a)/56.5005","CIT_ORD_SAFE":"Citation","LIKELIHOOD":"Reasonably","INJ_ILLNESS":"Permanent","NO_AFFECTED":"1","NEGLIGENCE":"LowNegligence","TERMINATION_DT":"07/18/2023","PROPOSED_PENALTY":"143","AMOUNT_DUE":"143","AMOUNT_PAID":"143","CONTESTED_IND":"N","sourceDate":"2023-07-05"},{"SOURCE_ROW_NUMBER":"1387918","VIOLATION_NO":"9625385","VIOLATION_ISSUE_DT":"06/07/2023","SIG_SUB":"N","PART_SECTION":"56.13015(a)","CIT_ORD_SAFE":"Citation","LIKELIHOOD":"Unlikely","INJ_ILLNESS":"LostDays","NO_AFFECTED":"1","NEGLIGENCE":"ModNegligence","TERMINATION_DT":"06/20/2023","PROPOSED_PENALTY":"143","AMOUNT_DUE":"143","AMOUNT_PAID":"143","CONTESTED_IND":"N","sourceDate":"2023-06-07"}]}],"safety":{"href":"/api/v1/mines/2104045/safety","description":"Full-period safety series, top CFR sections and paginated activity. Requires PostgreSQL."},"silica":{"href":"/api/v1/mines/2104045/silica","description":"Dedicated silica records, measurements, sample status and trends. Defaults to the snapshot year; use year=all for history."},"externalContext":{"eia":null,"title30":{"snapshot":{"chapterCount":6,"featuredSectionCount":100,"latestAmendedOn":"2026-08-14","latestIssueDate":"2026-08-14","partCount":206,"sectionCount":5954,"upToDateAsOf":"2026-08-19"},"regulations":[{"chapter":"I","heading":"Exposure limits for airborne contaminants.","officialUrl":"https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-D/section-56.5001","part":"56","subchapter":"K","subpart":"D","id":"56.5001","citation":"30 CFR 56.5001","chapterHeading":"CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR","subchapterHeading":"SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH","partHeading":"PART 56—SAFETY AND HEALTH STANDARDS—SURFACE METAL AND NONMETAL MINES","subpartHeading":"","text":null,"occurrenceCount":1},{"chapter":"I","heading":"Inspection of compressed-air receivers and other unfired pressure vessels.","officialUrl":"https://www.ecfr.gov/current/title-30/chapter-I/subchapter-K/part-56/subpart-L/section-56.13015","part":"56","subchapter":"K","subpart":"L","id":"56.13015","citation":"30 CFR 56.13015","chapterHeading":"CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR","subchapterHeading":"SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH","partHeading":"PART 56—SAFETY AND HEALTH STANDARDS—SURFACE METAL AND NONMETAL MINES","subpartHeading":"","text":null,"occurrenceCount":1}],"fullCorpus":"/data/title30-sections.json"}}},"meta":{"representation":"json","mineId":"2104045","dataSource":"postgres","snapshotId":"2026-10-13T11:19:05.459773+00:00","completedAt":"2026-10-13T11:26:59.401Z","sourceCount":20,"totalRows":17906804}}