Superfund Information Systems: Site Profile

Superfund Site:

CALIFORNIA GULCH
LEADVILLE, CO

Cleanup Progress

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Cleaning up Superfund sites is a complex, multi-phase process. Learn more:

Site-Wide Milestones

Milestone Date(s)
Preliminary Assessment/Site Investigation Completed 08/30/1982
Proposed to the National Priorities List 12/30/1982
Finalized on the National Priorities List 09/08/1983
Remedy Selected 03/29/1988
Final Remedy Selected 09/28/2010
Remedial Action Started 09/07/1988
Construction Completed Not Yet Achieved
Deleted from National Priorities List Not Yet Achieved
Most Recent Five-Year Review 09/29/2017
Site Ready for Reuse and Redevelopment Not Yet Achieved

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Cleanup Schedule by Operable Unit

During cleanup, a site can be divided into a number of distinct areas depending on its complexity. These areas, called operable units (OUs), may address geographic areas, specific problems, or areas where a specific action is required. Examples of typical operable units include construction of a groundwater pump and treatment system or construction of a cap over a landfill.

Milestone OU Start Date Completion Date OU ID
Removal OU 00 - SITEWIDE 02/15/1986 05/29/1986 00
Removal OU 00 - SITEWIDE 06/04/1993 06/04/1993 00
Removal OU 00 - SITEWIDE 09/09/1994 09/20/1994 00
Removal OU 00 - SITEWIDE 12/14/1990 08/31/1992 00
Five-Year Review OU 00 - SITEWIDE 02/02/1996 00
Five-Year Review OU 00 - SITEWIDE 09/27/2012 00
Five-Year Review OU 00 - SITEWIDE 09/28/2001 00
Five-Year Review OU 00 - SITEWIDE 09/28/2007 00
Five-Year Review OU 00 - SITEWIDE 09/29/2017 00
Remedial Investigation OU 01 - YAK TUNNEL 06/04/1992 09/27/1996 01
Feasibility Study OU 01 - YAK TUNNEL 07/05/2000 01/07/2005 01
Combined Remedial Investigation/Feasibility Study OU 01 - YAK TUNNEL 12/30/1983 03/29/1988 01
Record of Decision OU 01 - YAK TUNNEL 03/29/1988 01
Record of Decision Amendment OU 01 - YAK TUNNEL 03/23/1989 01
Remedial Design OU 01 - YAK TUNNEL 04/05/1988 03/02/1989 01
Remedial Design OU 01 - YAK TUNNEL 04/25/1989 05/03/1991 01
Remedial Design OU 01 - YAK TUNNEL 04/29/1993 09/27/1993 01
Remedial Action OU 01 - YAK TUNNEL 03/29/1994 11/09/1994 01
Remedial Action OU 01 - YAK TUNNEL 09/04/1990 02/08/1992 01
Remedial Action OU 01 - YAK TUNNEL 09/07/1988 06/28/1991 01
Operation and Maintenance OU 01 - YAK TUNNEL 11/03/1989 01
Partial NPL Deletion OU 01 - YAK TUNNEL 04/11/2016 01
Removal OU 02 - HECLA TAILINGS 05/03/2004 05/28/2004 02
Removal OU 02 - HECLA TAILINGS 05/26/1998 07/02/1998 02
Removal OU 02 - HECLA TAILINGS 07/31/1995 08/18/1998 02
Removal OU 02 - HECLA TAILINGS 08/31/1995 08/18/1998 02
Removal OU 02 - HECLA TAILINGS 08/31/1996 08/18/1998 02
Combined Remedial Investigation/Feasibility Study OU 02 - HECLA TAILINGS 04/07/1987 08/26/1993 02
Combined Remedial Investigation/Feasibility Study OU 02 - HECLA TAILINGS 08/17/1994 08/26/1994 02
Combined Remedial Investigation/Feasibility Study OU 02 - HECLA TAILINGS 09/10/1993 08/26/1994 02
Record of Decision OU 02 - HECLA TAILINGS 09/30/1999 02
Operation and Maintenance OU 02 - HECLA TAILINGS 05/28/2004 02
Partial NPL Deletion OU 02 - HECLA TAILINGS 07/23/2001 02
Combined Remedial Investigation/Feasibility Study OU 03 - DRG & W SLAG PILES 03/02/1994 08/26/1994 03
Combined Remedial Investigation/Feasibility Study OU 03 - DRG & W SLAG PILES 08/26/1994 09/27/1996 03
Record of Decision OU 03 - DRG & W SLAG PILES 05/06/1998 03
Partial NPL Deletion OU 03 - DRG & W SLAG PILES 04/11/2016 03
Removal OU 04 - UPPER CAL GULCH 07/19/1996 06/30/1998 04
Removal OU 04 - UPPER CAL GULCH 08/04/1995 06/30/1998 04
Removal OU 04 - UPPER CAL GULCH 10/31/1995 06/30/1998 04
Feasibility Study OU 04 - UPPER CAL GULCH 05/05/1995 03/21/1997 04
Combined Remedial Investigation/Feasibility Study OU 04 - UPPER CAL GULCH 02/03/1994 08/26/1994 04
Combined Remedial Investigation/Feasibility Study OU 04 - UPPER CAL GULCH 04/07/1987 08/26/1994 04
Combined Remedial Investigation/Feasibility Study OU 04 - UPPER CAL GULCH 12/15/1992 08/26/1994 04
Record of Decision OU 04 - UPPER CAL GULCH 03/31/1998 04
Remedial Design OU 04 - UPPER CAL GULCH 03/31/1998 07/28/1998 04
Remedial Action OU 04 - UPPER CAL GULCH 07/28/1998 09/02/2003 04
Operation and Maintenance OU 04 - UPPER CAL GULCH 09/02/2003 04
Partial NPL Deletion OU 04 - UPPER CAL GULCH 10/24/2014 04
Feasibility Study OU 05 - SMELTERS/MILL SITES 05/10/1999 09/29/2000 05
Combined Remedial Investigation/Feasibility Study OU 05 - SMELTERS/MILL SITES 08/29/1994 10/31/2000 05
Record of Decision OU 05 - SMELTERS/MILL SITES 09/29/2000 05
Record of Decision OU 05 - SMELTERS/MILL SITES 10/31/2000 05
Remedial Design OU 05 - SMELTERS/MILL SITES 02/22/2001 09/22/2004 05
Remedial Action OU 05 - SMELTERS/MILL SITES 09/22/2004 02/17/2010 05
Operation and Maintenance OU 05 - SMELTERS/MILL SITES 10/01/2012 05
Partial NPL Deletion OU 05 - SMELTERS/MILL SITES 10/24/2014 05
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 02/19/2008 09/29/2009 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 05/01/1996 08/19/1998 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 05/01/2015 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 05/22/2014 09/30/2014 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 06/24/1997 12/28/2000 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 06/25/2001 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 06/30/2000 10/13/2000 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 07/26/1996 10/04/1999 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 08/14/2012 11/12/2012 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 08/24/1995 08/19/1998 06
Removal OU 06 - HAMM'S TAILINGS/PENROSE DUMP 10/26/1998 12/28/2000 06
Feasibility Study OU 06 - HAMM'S TAILINGS/PENROSE DUMP 03/30/1994 08/26/1994 06
Feasibility Study OU 06 - HAMM'S TAILINGS/PENROSE DUMP 08/14/2009 09/28/2010 06
Feasibility Study OU 06 - HAMM'S TAILINGS/PENROSE DUMP 12/09/1999 09/11/2002 06
Combined Remedial Investigation/Feasibility Study OU 06 - HAMM'S TAILINGS/PENROSE DUMP 12/01/1991 08/26/1994 06
Record of Decision OU 06 - HAMM'S TAILINGS/PENROSE DUMP 09/25/2003 06
Record of Decision Amendment OU 06 - HAMM'S TAILINGS/PENROSE DUMP 09/28/2010 06
Remedial Design OU 06 - HAMM'S TAILINGS/PENROSE DUMP 05/11/2004 08/15/2006 06
Remedial Design OU 06 - HAMM'S TAILINGS/PENROSE DUMP 07/28/2011 09/06/2012 06
Remedial Design OU 06 - HAMM'S TAILINGS/PENROSE DUMP 09/20/2011 06
Remedial Action OU 06 - HAMM'S TAILINGS/PENROSE DUMP 04/23/2012 06/13/2013 06
Removal OU 07 - APACHE TAILINGS 04/07/1997 06/30/1998 07
Removal OU 07 - APACHE TAILINGS 08/08/1996 06/30/1998 07
Removal OU 07 - APACHE TAILINGS 10/04/1999 10/29/1999 07
Feasibility Study OU 07 - APACHE TAILINGS 09/16/1993 08/26/1994 07
Combined Remedial Investigation/Feasibility Study OU 07 - APACHE TAILINGS 08/26/1994 06/06/2000 07
Record of Decision OU 07 - APACHE TAILINGS 06/06/2000 07
Remedial Design OU 07 - APACHE TAILINGS 06/06/2000 07/02/2001 07
Remedial Action OU 07 - APACHE TAILINGS 07/02/2001 12/17/2003 07
Operation and Maintenance OU 07 - APACHE TAILINGS 08/28/2007 07
Operation and Maintenance OU 07 - APACHE TAILINGS 12/17/2003 08/28/2007 07
Partial NPL Deletion OU 07 - APACHE TAILINGS 10/24/2014 07
Removal OU 08 - LOWER CAL GULCH 06/11/1998 02/05/1999 08
Removal OU 08 - LOWER CAL GULCH 08/04/1995 06/30/1998 08
Combined Remedial Investigation/Feasibility Study OU 08 - LOWER CAL GULCH 08/26/1994 09/29/2000 08
Record of Decision OU 08 - LOWER CAL GULCH 09/29/2000 08
Remedial Design OU 08 - LOWER CAL GULCH 05/11/2001 07/22/2002 08
Remedial Action OU 08 - LOWER CAL GULCH 07/22/2002 09/02/2003 08
Operation and Maintenance OU 08 - LOWER CAL GULCH 09/02/2003 08
Partial NPL Deletion OU 08 - LOWER CAL GULCH 01/12/2010 08
Removal OU 09 - RESIDENTIAL SOIL 01/08/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 04/01/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 05/30/1996 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 06/08/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 06/10/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 06/15/2009 08/19/2009 09
Removal OU 09 - RESIDENTIAL SOIL 07/01/1996 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 07/07/1996 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 07/07/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 07/12/1999 10/12/1999 09
Removal OU 09 - RESIDENTIAL SOIL 07/17/2006 08/23/2007 09
Removal OU 09 - RESIDENTIAL SOIL 07/24/1998 04/21/2000 09
Removal OU 09 - RESIDENTIAL SOIL 07/30/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 08/15/1996 08/14/2001 09
Removal OU 09 - RESIDENTIAL SOIL 08/17/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 08/29/1996 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 08/30/1996 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 09/12/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 09/12/1997 07/22/1998 09
Removal OU 09 - RESIDENTIAL SOIL 09/17/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 09/19/2005 08/14/2006 09
Removal OU 09 - RESIDENTIAL SOIL 09/24/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 10/01/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 10/03/2016 10/16/2016 09
Removal OU 09 - RESIDENTIAL SOIL 10/05/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 10/06/1999 10/28/1999 09
Removal OU 09 - RESIDENTIAL SOIL 10/21/1997 05/26/1998 09
Removal OU 09 - RESIDENTIAL SOIL 10/21/1999 10/28/1999 09
Removal OU 09 - RESIDENTIAL SOIL 10/22/1998 12/15/1998 09
Removal OU 09 - RESIDENTIAL SOIL 11/11/1999 04/21/2000 09
Removal OU 09 - RESIDENTIAL SOIL 11/29/1999 12/01/1999 09
Removal OU 09 - RESIDENTIAL SOIL 12/01/1997 12/15/1998 09
Remedial Investigation OU 09 - RESIDENTIAL SOIL 05/05/1994 08/26/1994 09
Combined Remedial Investigation/Feasibility Study OU 09 - RESIDENTIAL SOIL 08/26/1994 09/02/1999 09
Combined Remedial Investigation/Feasibility Study OU 09 - RESIDENTIAL SOIL 09/15/1993 08/26/1994 09
Combined Remedial Investigation/Feasibility Study OU 09 - RESIDENTIAL SOIL 12/18/1992 08/26/1994 09
Combined Remedial Investigation/Feasibility Study OU 09 - RESIDENTIAL SOIL 12/18/1992 08/28/1994 09
Record of Decision OU 09 - RESIDENTIAL SOIL 09/02/1999 09
Remedial Design OU 09 - RESIDENTIAL SOIL 09/02/1999 12/29/2000 09
Remedial Action OU 09 - RESIDENTIAL SOIL 06/13/2000 09
Remedial Action OU 09 - RESIDENTIAL SOIL 01/24/2011 09
Operation and Maintenance OU 09 - RESIDENTIAL SOIL 10/21/2010 09
Partial NPL Deletion OU 09 - RESIDENTIAL SOIL 04/22/2002 09
Partial NPL Deletion OU 09 - RESIDENTIAL SOIL 09/21/2011 09
Removal OU 10 - OREGON GULCH 08/04/1995 06/30/1998 10
Combined Remedial Investigation/Feasibility Study OU 10 - OREGON GULCH 08/28/1994 12/05/1996 10
Record of Decision OU 10 - OREGON GULCH 08/08/1997 10
Remedial Design OU 10 - OREGON GULCH 11/04/1997 06/03/1998 10
Remedial Action OU 10 - OREGON GULCH 06/03/1998 09/30/1999 10
Operation and Maintenance OU 10 - OREGON GULCH 09/30/1999 10
Partial NPL Deletion OU 10 - OREGON GULCH 04/16/2001 10
Removal OU 11 - ARKANSAS FLOOD PLAIN 07/26/1999 10/26/2007 11
Removal OU 11 - ARKANSAS FLOOD PLAIN 08/10/2000 10/26/2007 11
Removal OU 11 - ARKANSAS FLOOD PLAIN 09/23/1997 10/26/2007 11
Combined Remedial Investigation/Feasibility Study OU 11 - ARKANSAS FLOOD PLAIN 08/06/2001 09/28/2005 11
Record of Decision OU 11 - ARKANSAS FLOOD PLAIN 09/28/2005 11
Remedial Design OU 11 - ARKANSAS FLOOD PLAIN 09/27/2005 09/17/2007 11
Remedial Action OU 11 - ARKANSAS FLOOD PLAIN 09/13/2006 09/19/2013 11
Operation and Maintenance OU 11 - ARKANSAS FLOOD PLAIN 05/01/2017 11
Removal OU 12 - SITE-WIDE WATER QUALITY 05/01/2015 12
Combined Remedial Investigation/Feasibility Study OU 12 - SITE-WIDE WATER QUALITY 08/26/1994 09/22/2009 12
Record of Decision OU 12 - SITE-WIDE WATER QUALITY 09/22/2009 12
Remedial Design OU 12 - SITE-WIDE WATER QUALITY 09/03/2013 04/29/2015 12
Remedial Action OU 12 - SITE-WIDE WATER QUALITY 09/23/2014 12

DISCLAIMER: The data on this page are derived from the Superfund Enterprise Management System and are solely for informational purposes. The data cannot be relied upon to create any substantive or procedural rights or requirements enforceable by any party in litigation with any member of the public, states, tribes, the United States or any federal agency. EPA reserves the right to change these data at any time without public notice.

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