At least 52 properties, located in the City of Leadville, Colorado, are addressed by this Removal Action. The Properties have areas where the concentrations of lead in soil exceed the soil action levels of 3,500 parts per million (ppm).
The Properties are within OU 9 of the California Gulch Superfund Site (Site). The Leadville area, including portions of OU9, was the site of extensive mining, milling, and smelting operations that began about 1860. Most mining operations ceased around 1900, although some facilities continued intermittent operations as late as the 1960s. Most of the mines within the Site boundary are presently inactive and all of the mills and smelters have been demolished. Site investigations showed the presence of heavy metals in soils and in waste piles in and around the current residential area of Leadville.
Since the initial access agreements were obtained from the property owners by ASARCO’s contractor, EPA chose to have new accesses signed. This was initiated on July 11, 2006, at a meeting with those owners on a list supplied by MFG, Co. (ASARCO’s contractor). Plats constructed by ASARCO were reviewed with the owners on-site and most were modified prior to being signed by the property owner and the OSC. All the properties are being videoed prior to the removal and will be re-done after the restoration (after there is plant growth). A final copy of the signed design plat with the lead concentrations at the base of the dig will be prepared and given to the owner along with a letter of certification of the removal completion and the make up of native grass or sod.
The initial action was a meeting on July 11, 2006, by the OSC and other EPA representatives with the owners of the properties as listed by ASARCO’s contractor. At the meeting, some of the property owners signed a newer access form drawn up by the EPA. Then on July 17, 2006, the OSC, EPA’s Superfund Technical Assistance Team (START) Contractor, and EPA’s Emergency and Rapid Response Services (ERRS), responded to the Site and initiated the following activities:
The OSC visited the owners of the signed access forms and constructed design plats of the property which detailed the removal process to be accomplished by ERRS. START acquired additional signed access forms, made digital videos prior to removal, collected some samples and planned the post removal sampling and videos.
ERRS, using the above information, either removed six or twelve inches based on the sampling completed by ASARCO’s contractor. Replacement was a combination of clean fill and top soil. The owners requested sod or high altitude grass/wildflower mixes which were planted and initially watered by ERRS.
During the removal, the contaminated material was placed in the Iron Hat Quarry. The clean fill material was removed from the Leadville Silver & Gold Borrow Pit and screened initially to a minus three inch size, then later to a minus two inch size.
The top soil came from an ASARCO pit located south of town and just southeast of the Leadville Rod and Gun Club. Samples of the top soil were sent to Colorado State University at Ft. Collins for analysis.
Initially, fifty two projects were designated as needing to be remediated. Several more were added during the summer, making a current total of fifty seven projects. There is a wide variability in the sizes of the projects from full size lots (30x125’) to a hot spot of 10x20’. Of the fifty seven:
Twenty one are completely done and signed off.
Fifteen are completely done and sign off forms have been sent for signatures.
Seven are done and sign off forms have been sent; however, the sprouting of grass and/or wildflower mixtures will need to be verified in the spring of 2007.
Two owners have not been found.
Eight projects are scheduled for a 2007 removal.
One was extensively sampled and Lead
concentrations were below the action level.
Two were driveway repairs of work done in the
summer of 2005.
One from the 2005 summer work is awaiting
repairs to be done in 2007.
The approximate amounts of material removed and replaced is as follows:
Contaminated soil, grass, debris = 5441 yd3
Backfill = 1884 “
Top Soil = 2088 “
Roadba = 860 “
Sand, gravel, rocks = 168 “
• In 2007 site activities, listed above, will be completed on at least eight residences.
• Water will be used during the removals if necessary to mitigate any fugitive dust.
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