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NPL Partial Site Deletion Narrative

California Gulch
Leadville, Colorado

Partial Site Deletion Federal Register Notice: September 21, 2011 (PDF) (2 pp, 145K, About PDF)

On September 21, 2011, EPA deleted a portion of the California Gulch Superfund site from the National Priorities List (NPL). This partial deletion pertains to the remaining portions of operable unit (OU) 9, Residential Populated Areas. The California Gulch site is located in Lake County, Colorado approximately 100 miles southwest of Denver. The site is in a highly mineralized area of the Colorado Rocky Mountains covering approximately 18 square miles of a watershed that drains along California Gulch to the Arkansas River. According to the 1994 Consent Decree, the site was divided into 12 OUs in order to expedite clean-up.

OU9 includes residential area soils in those portions of the site where the land use is currently residential or that were zoned as residential areas on or before September 2, 1999. Residential area soils are defined as soils in residential areas which may have been impacted by past smelting and mining activities. This encompasses the City of Leadville, Stringtown and outlying areas zoned for residential use. The State of Colorado, EPA and Potentially Responsible Parties have conducted various studies and investigations to evaluate the nature and extent of contamination. In 1991, Remedial Investigations began for several areas and it was determined that lead in soils is the primary contaminant of concern in OU9.

Under the 1994 CD, ASARCO assumed responsibility for OU9 and agreed to undertake actions to address all sources of lead in lieu of soil removal only at each residence. To determine the effectiveness of the actions, the level of lead in children's blood was voluntarily monitored and performance standards in relation to concentrations of lead in the blood of children were established. In 1995, ASARCO began implementing Kids First Program (KF) as an interim response action until EPA selected a remedy for OU9. The OU9 Record of Decision was signed on September 2, 1999, selecting the Lake County Community Health Program (LCCHP), a revised version of the KF program, as the remedy. The LCCHP combined blood-lead monitoring, education, community awareness, and residence specific response actions. This program addressed lead in soil and dust, interior and exterior paint, plumbing fixtures, and dietary and household sources. It also included institutional controls (ICs) to ensure effectiveness of the LCCHP. Operation and maintenance activities included LCCHP administration and the blood-lead monitoring program.

Several time removal actions were conducted from October 1995 to April 2000 under the KF program. More time critical removal actions were completed under the LCCHP from April 2000 to the summer of 2009 on multiple residences, commercial properties and vacant lots. From October 1995 to the summer of 2009, 1,040 properties were investigated. 270 of those properties required a soil removal action. Forty properties, which may or may not have had soil removals, have had dust removed or paint repaired/replaced. The EPA conducted the last property assessment and response actions in the summer of 2009.

On March 15, 2010, Lake County passed a resolution approving the LCCHP Phase 2 Work Plan and adopting the LCCHP Phase 2 as an IC for OU9. A separate county resolution was passed on December 23, 2009 amending the Lake County Land Development Code Chapter 3.2. The Lake County Building and Land Use Department (LCBLUD) is required to provide building permit applicants within the boundaries of the remaining 38 mine waste piles in OU9 with a handout regarding Best Management Practices for managing potentially contaminated soils in Lake County. Each applicant is obligated to sign a document attesting to the fact that he/she received, read and understood the Lake County Best Management handout. No building permit will be issued without the applicant's written acknowledgement provided to the LCBLUD. Additionally, written proof of approval from the CDPHE is a condition precedent to issuance of a building permit by the LCBLUD.

The EPA, with concurrence of the State of Colorado through the Colorado Department of Public Health and Environment has determined that all appropriate response actions under CERCLA, other than operation, maintenance, monitoring and five-year reviews, have been completed. Therefore, EPA is deleting remaining portions of OU9, Residential Populated Areas from the NPL.

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