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   Party At-A-Glance Report

  
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General Information
Party ID Party Name Party Classification Mailing Address Work Phone Email/Website
487446 MP Mine Operations LLC Privately-Owned Business 67750 Bailey Road Mountain Pass, CA 92366 702-540-2787 sbaker@mpmaterials.com
  
  
  
  
Expand/Contract Related Places
Related Places
Place ID Place Name County Region Place Type Relationship to Party Relationship Start Date Relationship End Date
220454 DOMESTIC WASTEWATER T&DFs San Bernardino 6B Wastewater Treatment Facility Owner 07/12/2017 None
246044 Onsite Evaporation Ponds San Bernardino 6B Surface Impoundment Owner 07/12/2017 None
215314 COMMUNITY & CO LANDFILLS-Molycorp San Bernardino 6B Land fill Owner 07/12/2017 None
244589 North Tailing Pond P-16 San Bernardino 6B Metal Mining Owner 07/12/2017 None
241610 Mountain Pass Mine & Mill Ops San Bernardino 6B Metal Mining Owner 07/12/2017 None
757215 Mountain Pass Mine-Revised Mine & Reclamation Plan San Bernardino 6B Dredge/Fill Site Owner 09/28/2010 None
241611 Mountain Pass P-1 Closure San Bernardino 6B Metal Mining Owner 07/12/2017 None
890508 North Overburden Stockpile Development MPMO San Bernardino 6B Dredge/Fill Site Owner 09/25/2023 None
Total Related Places: 8
  
  
  
  
Expand/Contract Related Parties
Related Parties
Party ID Party Name Party Type Role/Relationship Relationship Start Date Relationship End Date Classification
622685 Steven Baker Person Legally Responsible Official 03/11/2021 None None
629234 Aaron Case Person Employee 08/01/2019 None None
508765 Mark Smith Person Owner Contact 06/01/2009 07/11/2017 None
605017 John Espinoza Person Employee 07/12/2017 None None
547600 Jeffrey Hogan Person Legally Responsible Official 07/16/2014 07/11/2017 None
Total Related Parties: 5
  
  
  
  
Expand/Contract Regulatory Measures
Regulatory Measures (non-enforcement)
Reg. Measure ID Regulatory Measure Type Region WDID Status Program Order No. RM Effective Date RM Termination Date Relationship Relationship Start Date Relationship End Date Amended?
454473 Enrollee - WDR 6V 6B362309006 Active CERFILLEXC R6T-2003-0004 03/18/2024 None Discharger 09/25/2023 None N
376674 Enrollee - 401 Certification 6V 6B361009001 Historical CERFILLEXC R6T-2003-0004 12/02/2010 12/02/2020 Discharger 09/28/2010 None N
306717 WDR 6V 6B369706002 Active LFNONOPER R6V-2006-0024 06/14/2006 None Discharger 07/10/2017 None N
145895 WDR 6V 6B362098001 Historical LNDISP 91-836 06/13/1991 10/14/2010 Discharger 06/01/2009 None N
377626 WDR 6V 6B362098001 Active LNDISPOTH R6V-2010-0047 10/14/2010 None Discharger 07/10/2017 None N
132920 WDR 6V 6B360009001 Active LNDISPOTH R6V-2004-0042 10/14/2004 None Discharger 07/10/2017 None N
148001 WDR 6V 6B360008001 Active LNDISPOTH 00-074 09/14/2000 None Discharger 07/10/2017 None N
133369 WDR 6V 6B369807003 Active LNDISPOTH R6V-2005-0011 04/14/2005 None Discharger 07/10/2017 None N
388260 Enrollee - WDR 6V 6B360011004 Active WDRMUNIENROTH 97-010-DWQ 11/07/2012 None Discharger 06/01/2009 None N
148025 WDR 6V 6B360011004 Historical WDRMUNIOWTS 01-018 04/11/2001 06/19/2013 Discharger 06/01/2009 None N
Total Regulatory Measures: 10
  
  
  
  
Expand/Contract Violations
Violations within the past year
Violation ID Occurrence Date Violation Type Violation Description(+) Violation Status Priority Source Facility Name Violated Reg. Meas. ID Violated Reg. Meas. Order No. Linked to Enf.
1144261 03/17/2025 Unauthorized Discharge 325 gallons of sodium hydroxide spilled. Release was stopped for line repair. On Violation N Report Mountain Pass Mine & Mill Ops 377626 R6V-2010-0047 N
1144258 09/06/2024 Unauthorized Discharge Cal-OES 24-5040 Line failure caused 32% sodium hydroxide spill onto ground. MPMO Violation N Report Mountain Pass Mine & Mill Ops 377626 R6V-2010-0047 N
Report defaults to display violations within the last year. Click here to see last five years of violations. Refer to the Interactive Violation Report for more data.
Total Violations: 2
*Click the "(+/-) Violation Description" link to expand and contract the violation description.
  
  
  
  
Expand/Contract Enforcement Actions
Enforcement Actions
Enforcement ID Enforcement Type Enf. Order No. Title Program Effective Date Status
382364 Oral Communication None Molycorp Minerals LLC Spill (11/28/2011) LNDISP 11/28/2011 Historical
388244 Oral Communication None Oral Com 11/27/2012 for Molycorp Minerals LLC LNDISP 11/27/2012 Historical
389533 Oral Communication None Oral Com 09/14/2012 for Molycorp Minerals LLC LNDISP 09/14/2012 Historical
390178 Oral Communication None Oral Com 02/28/2013 for Molycorp Minerals LLC LNDISP 02/28/2013 Historical
394953 Oral Communication None Oral Com 01/09/2014 for Molycorp Minerals LLC WDRMUNIENROTH 01/09/2014 Historical
396973 Oral Communication None Oral Com 09/20/2013 for Molycorp Minerals LLC LNDISPOTH 09/20/2013 Historical
399719 Oral Communication None Oral Com 01/12/2015 for Molycorp Minerals LLC LNDISPOTH 01/12/2015 Historical
399720 Oral Communication None Oral Com 01/15/2015 for Molycorp Minerals LLC LNDISPOTH 01/15/2015 Historical
402399 Oral Communication None Oral Com 07/29/2015 for Molycorp Minerals LLC LNDISPOTH 07/29/2015 Historical
423504 Oral Communication None Oral Com 08/14/2018 for MP Mine Operations LLC LFNONOPER 08/14/2018 Historical
449817 Oral Communication None Oral Com 05/27/2022 for MP Mine Operations LLC LNDISPOTH 05/27/2022 Historical
380390 Staff Enforcement Letter None SEL 07/20/2011 for Molycorp Minerals LLC LNDISP 07/20/2011 Historical
381973 Oral Communication None Molycorp Minerals LLC spill ( 10/10/2011) LNDISP 10/24/2011 Historical
384026 Oral Communication None Oral Com 03/29/2012 for Molycorp Minerals LLC LNDISP 03/29/2012 Historical
394464 Oral Communication None Oral Com 10/08/2013 for Molycorp Minerals LLC LNDISP 10/08/2013 Historical
394956 Oral Communication None Oral Com 01/21/2014 for Molycorp Minerals LLC WDRMUNIENROTH 01/21/2014 Historical
394958 Oral Communication None Oral Com 11/14/2013 for Molycorp Minerals LLC WDRMUNIENROTH 11/14/2013 Historical
396974 Oral Communication None Oral Com 09/23/2013 for Molycorp Minerals LLC LNDISPOTH 09/23/2013 Historical
397929 Oral Communication None Oral Com 08/07/2014 for Molycorp Minerals LLC LNDISPOTH 08/07/2014 Historical
402179 Oral Communication None Oral Com 07/21/2015 for Molycorp Minerals LLC LNDISPOTH 07/21/2015 Historical
425637 Oral Communication None Oral Com 10/11/2018 for MP Mine Operations LLC LNDISPOTH 10/11/2018 Historical
387328 Oral Communication None Oral Com 08/09/2012 for Molycorp Minerals LLC LNDISP 08/09/2012 Historical
388134 Oral Communication None Oral Com 11/06/2012 for Molycorp Minerals LLC LNDISP 11/06/2012 Historical
388942 Notice of Violation None NOV 01/29/2013 for Molycorp Minerals LLC LNDISP 01/29/2013 Historical
389048 Oral Communication None Oral Com 06/01/2012 for Molycorp Minerals LLC LNDISP 06/01/2012 Historical
395386 Oral Communication None Oral Com 02/28/2014 for Molycorp Minerals LLC LNDISP 02/28/2014 Historical
395610 Oral Communication None Oral Com 04/04/2014 for Molycorp Minerals LLC LNDISPOTH 04/04/2014 Historical
397308 Oral Communication None Oral Com 06/09/2014 for Molycorp Minerals LLC LNDISPOTH 06/09/2014 Historical
397332 Oral Communication None Oral Com 07/09/2014 for Molycorp Minerals LLC LNDISPOTH 07/09/2014 Historical
397928 Oral Communication None Oral Com 07/23/2014 for Molycorp Minerals LLC LNDISPOTH 07/23/2014 Historical
399515 Oral Communication None Oral Com 12/15/2014 for Molycorp Minerals LLC LNDISPOTH 12/15/2014 Historical
399730 Oral Communication None Oral Com 01/20/2015 for Molycorp Minerals LLC LNDISPOTH 01/20/2015 Historical
419741 Oral Communication None Oral Com 02/21/2018 for MP Mine Operations LLC LNDISPOTH 02/21/2018 Historical
382499 Oral Communication None Molycorp Minerals LLC Spill (12/8/2011) LNDISP 12/08/2011 Historical
384029 Oral Communication None Oral Com 02/10/2012 for Molycorp Minerals LLC LNDISP 02/10/2012 Historical
390179 Oral Communication None Oral Com 03/08/2013 for Molycorp Minerals LLC LNDISP 03/08/2013 Historical
390181 Oral Communication None Oral Com 04/11/2013 for Molycorp Minerals LLC LNDISP 04/11/2013 Historical
394347 Oral Communication None Oral Com 12/16/2013 for Molycorp Minerals LLC LNDISP 12/16/2013 Historical
394385 Notice of Violation None NOV 12/24/2013 for Molycorp Minerals LLC LNDISP 12/24/2013 Historical
394461 Oral Communication None Oral Com 12/16/2013 for Molycorp Minerals LLC LNDISP 12/16/2013 Historical
428307 Oral Communication None Oral Com 01/02/2019 for MP Mine Operations LLC LNDISPOTH 01/02/2019 Historical
423519 Oral Communication None Oral Com 08/14/2018 for MP Mine Operations LLC LNDISPOTH 08/14/2018 Historical
382062 Notice of Violation None NOV 10/27/2011 for Molycorp Minerals LLC LNDISP 10/27/2011 Historical
389493 Oral Communication None Oral Com 03/05/2013 for Molycorp Minerals LLC LNDISP 03/05/2013 Historical
390177 Oral Communication None Oral Com 01/16/2013 for Molycorp Minerals LLC LNDISP 01/16/2013 Historical
394469 Oral Communication None Oral Com 01/03/2014 for Molycorp Minerals LLC LNDISPOTH 01/03/2014 Historical
396142 Oral Communication None Oral Com 04/23/2014 for Molycorp Minerals LLC LNDISPOTH 04/23/2014 Historical
397167 Oral Communication None Oral Com 06/24/2014 for Molycorp Minerals LLC LNDISPOTH 06/24/2014 Historical
397331 Oral Communication None Oral Com 07/03/2014 for Molycorp Minerals LLC LNDISPOTH 07/03/2014 Historical
423561 Oral Communication None Oral Com 07/23/2018 for MP Mine Operations LLC LNDISPOTH 07/23/2018 Historical
381972 Oral Communication None Molycorp Minerals LLC Spill (10/9/2011) LNDISP 10/10/2011 Historical
389535 Oral Communication None Oral Com 06/01/2012 for Molycorp Minerals LLC LNDISP 06/01/2012 Historical
390176 Oral Communication None Oral Com 01/16/2013 for Molycorp Minerals LLC LNDISP 01/16/2013 Historical
396143 Oral Communication None Oral Com 05/05/2014 for Molycorp Minerals LLC LNDISPOTH 05/05/2014 Historical
428304 Oral Communication None Oral Com 01/02/2019 for MP Mine Operations LLC LNDISPOTH 01/02/2019 Historical
428308 Oral Communication None Oral Com 01/03/2019 for MP Mine Operations LLC LNDISPOTH 01/03/2019 Historical
423516 Oral Communication None Oral Com 08/14/2018 for MP Mine Operations LLC LNDISPOTH 08/14/2018 Historical
382362 Oral Communication None Molycorp Minerals LLC Spill (11/1/2011) LNDISP 11/01/2011 Historical
382505 Oral Communication None Oral Com 12/15/2011 for Molycorp Minerals LLC LNDISP 12/15/2011 Historical
387562 Oral Communication None Oral Com 09/12/2012 for Molycorp Minerals LLC LNDISP 09/12/2012 Historical
389534 Oral Communication None Oral Com 09/24/2012 for Molycorp Minerals LLC LNDISP 09/24/2012 Historical
394136 Oral Communication None Oral Com 12/05/2013 for Molycorp Minerals LLC LNDISP 12/05/2013 Historical
394463 Oral Communication None Oral Com 07/31/2013 for Molycorp Minerals LLC LNDISP 07/31/2013 Historical
394954 Oral Communication None Oral Com 01/21/2014 for Molycorp Minerals LLC WDRMUNIENROTH 01/21/2014 Historical
397002 Oral Communication None Oral Com 06/09/2014 for Molycorp Minerals LLC LNDISPOTH 06/09/2014 Historical
399516 Oral Communication None Oral Com 10/29/2014 for Molycorp Minerals LLC LNDISPOTH 10/29/2014 Historical
399517 Oral Communication None Oral Com 12/19/2014 for Molycorp Minerals LLC LNDISPOTH 12/19/2014 Historical
399866 Oral Communication None Oral Com 01/28/2015 for Molycorp Minerals LLC LNDISPOTH 01/28/2015 Historical
423505 Oral Communication None Oral Com 08/14/2018 for MP Mine Operations LLC LNDISPOTH 08/14/2018 Historical
423513 Oral Communication None Oral Com 08/14/2018 for MP Mine Operations LLC LNDISPOTH 08/14/2018 Historical
423514 Oral Communication None Oral Com 08/14/2018 for MP Mine Operations LLC LNDISPOTH 08/14/2018 Historical
429031 13267 Letter None 13260 Letter for GILTON RESOURCE RECOVERY TRANSFER FACILITY WDRINDIVSML 02/20/2019 Historical
388247 Oral Communication None Oral Com 11/27/2012 for Molycorp Minerals LLC LNDISP 11/27/2012 Historical
391807 Oral Communication None Oral Com 06/17/2013 for Molycorp Minerals LLC LNDISP 06/17/2013 Historical
392999 Staff Enforcement Letter None SEL 08/08/2013 for Molycorp Minerals LLC LNDISP 08/08/2013 Historical
394880 Oral Communication None Oral Com 01/15/2014 for Molycorp Minerals LLC LNDISP 01/15/2014 Historical
399518 Oral Communication None Oral Com 12/18/2014 for Molycorp Minerals LLC LNDISPOTH 12/18/2014 Historical
400262 Oral Communication None Oral Com 03/02/2015 for Molycorp Minerals LLC LNDISPOTH 03/02/2015 Historical
401788 Oral Communication None Oral Com 06/29/2015 for Molycorp Minerals LLC LNDISPOTH 06/29/2015 Historical
388275 Notice of Violation None NOV 11/20/2012 for Molycorp Minerals LLC LNDISPOTH 11/20/2012 Active
393507 Notice of Violation None NOV 10/10/2013 for Molycorp Minerals LLC LNDISPOTH 10/10/2013 Active
398937 Notice of Violation None NOV 11/20/2014 for Molycorp Minerals LLC LNDISPOTH 11/20/2014 Active
387074 Notice of Violation None NOV 06/08/2012 for Molycorp Minerals LLC LNDISPOTH 06/08/2012 Active
394379 Notice of Violation None NOV 12/20/2013 for Molycorp Minerals LLC LNDISP 12/20/2013 Active
397425 Clean-up and Abatement Order R6V-2014-0062 CAO R6V-2014-0062 for Molycorp Minerals LLC LNDISPOTH 07/22/2014 Active
Total Enforcement Actions: 85
  
  
  
  
Expand/Contract Enforcement Actions
Regulatory Measures linked to Related Parties
Reg. Measure ID Organization Regulatory Measure Type Program Effective Date Status
388260 Aaron Case Enrollee - WDR WDRMUNIENROTH 11/07/2012 Active
377626 John Espinoza WDR LNDISPOTH 10/14/2010 Active
306717 John Espinoza WDR LFNONOPER 06/14/2006 Active
133369 John Espinoza WDR LNDISPOTH 04/14/2005 Active
132920 John Espinoza WDR LNDISPOTH 10/14/2004 Active
148001 John Espinoza WDR LNDISPOTH 09/14/2000 Active
Total Regulatory Measures linked to Related Parties: 6
  
  
The current report was generated with data as of: 07/22/2025
Regional Boards are in the process of entering backlogged data.
As a result, data may be incomplete.
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