Superfund Information Systems: Site Profile

Superfund Site:

CALIFORNIA GULCH
LEADVILLE, CO

Operable Units

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Below, EPA has provided a list of the remedial actions selected pertaining to each operable unit.

EPA issues Records of Decision (RODs) to explain which cleanup methods will be used at Superfund National Priorities List sites. EPA has two primary documents that it may use to identify changes to the remedies selected in RODs. EPA uses a ROD Amendment when it needs to make a fundamental change to the remedy. EPA publishes an Explanation of Significant Differences (ESD) for significant changes.

During cleanup, complex sites may be divided into several distinct areas to make the response more efficient. These areas, called operable units (OUs), may address geographic areas, specific problems, or medium (e.g., groundwater, soil) where a specific action is required.

EPA is working to improve data quality. The information presented on this page is undergoing review for accuracy and completeness, and may be subject to change.

OU ID Name Decision Document Cleanup Technologies Selected
in the Decision Document
00 SITEWIDE No decision document
01 YAK TUNNEL Record of Decision
March 29, 1988
Clarification (sedimentation, P&T, exsitu)
Drainage/Erosion Control (other, NOS)
Engineering Control (other, NOS)
Hydraulic Control (containment)
Hydraulic Control (for water table adjustment)
Monitoring
Operations & Maintenance (O&M)
Treatment (other, NOS, exsitu, onsite)
01 YAK TUNNEL Record of Decision Amendment
March 23, 1989
Clarification (sedimentation, P&T, exsitu)
Drainage/Erosion Control (other, NOS)
Engineering Control (other, NOS)
Treatment (other, NOS, exsitu, onsite)
01 YAK TUNNEL Explanation of Significant Differences
April 01, 1989
Engineering Control (other, NOS)
01 YAK TUNNEL Explanation of Significant Differences
October 01, 1991
Drainage/Erosion Control (dike/berm/levee)
Hydraulic Control (containment)
01 YAK TUNNEL Explanation of Significant Differences
July 29, 2013
Institutional Controls
02 HECLA TAILINGS Record of Decision
September 30, 1999
Monitoring
No Action
No Further Action
02 HECLA TAILINGS Explanation of Significant Differences
July 29, 2013
ESD/Amd - ICs - Implement or Change
03 DRG & W SLAG PILES Record of Decision
May 06, 1998
No Action
03 DRG & W SLAG PILES Explanation of Significant Differences
August 06, 2014
Institutional Controls
04 UPPER CAL GULCH Record of Decision
March 31, 1998
Cap (engineered cap)
Consolidate (onsite)
Containment (other, NOS, onsite)
Drainage/Erosion Control (ditch)
Drainage/Erosion Control (other, NOS)
Revegetation
Wetlands Replacement
04 UPPER CAL GULCH Explanation of Significant Differences
March 17, 2004
ESD - Nonfundamental Change (other)
04 UPPER CAL GULCH Explanation of Significant Differences
July 29, 2013
Institutional Controls
05 SMELTERS/MILL SITES Record of Decision
September 29, 2000
Bottom Liner
Cap (engineered cap)
Consolidate (onsite)
Containment (other, NOS, onsite)
Cover (soil)
Demolition
Excavation
Institutional Controls
Monitoring
Revegetation
05 SMELTERS/MILL SITES Record of Decision
October 31, 2000
Institutional Controls
No Action
06 HAMM'S TAILINGS/PENROSE DUMP Record of Decision
September 25, 2003
Containment (other, NOS, onsite)
Discharge (other, NOS)
Drainage/Erosion Control (dike/berm/levee)
Evaporation (P&T, exsitu)
Institutional Controls
Monitoring
Operations & Maintenance (O&M)
Treatment (other, NOS, exsitu, onsite)
Treatment (other, NOS, onsite)
06 HAMM'S TAILINGS/PENROSE DUMP Record of Decision Amendment
September 28, 2010
Cap (engineered cap)
Containment (other, NOS, onsite)
ESD - Nonfundamental Change (other)
07 APACHE TAILINGS Record of Decision
June 06, 2000
Cap (engineered cap)
Consolidate (onsite)
Drainage/Erosion Control (other, NOS)
Excavation
Institutional Controls
Monitoring
Revegetation
Slope Stabilization
08 LOWER CAL GULCH Record of Decision
September 29, 2000
Containment (other, NOS, onsite)
Drainage/Erosion Control (other, NOS)
No Action
No Further Action
Revegetation
09 RESIDENTIAL SOIL Record of Decision
September 02, 1999
Containment (other, NOS, onsite)
Decontamination
Excavation
Institutional Controls
Monitoring
Operations & Maintenance (O&M)
Other (NOS)
10 OREGON GULCH Record of Decision
August 08, 1997
Cap (engineered cap)
Cap (exsitu)
Drainage/Erosion Control (ditch)
Extraction (recovery trench/subsurface collection drain)
Impermeable Barrier
Pumping
Revegetation
Treatment (other, NOS, exsitu, onsite)
10 OREGON GULCH Explanation of Significant Differences
July 29, 2013
Institutional Controls
11 ARKANSAS FLOOD PLAIN Record of Decision
September 28, 2005
Institutional Controls
Monitoring
Revegetation
Soil Amendments
Treatment (other, NOS, insitu)
12 SITE-WIDE WATER QUALITY Record of Decision
September 22, 2009
Institutional Controls
Monitoring

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