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Valmont Butte Project

Valmont Butte Project

The City of Boulder project at Valmont Butte includes remediation of the site under the State of Colorado's Voluntary Cleanup Program (VCUP). Remediation was completed in 2014. Details of the completed work can be found in the Valmont Butte Property Construction Completion Report. pdf

The city submitted a request for annexation of the property in December 2015. The city's intent is to continue the historical designation of the mill buildings, preserve the 16 acres of undisturbed historic areas, keep the 27 acres of open space “as–is,” and use the remaining areas for future, low-impact city use. 

City staff is conducting a solar feasibility study for the site, with an expected completion date of early 2018 for the study. Also in 2018, staff will meet with Native American tribal members on uses and designations of the site.

Can community members tour the site?

Public access to the Valmont Butte mill buildings is not allowed for safety reasons. The structures are controlled by an environmental covenant through the Colorado Department of Public Health and the Environment. 

The rest of the site is undergoing revegetation, so tours are not being provided at this time.

Past Updates

2014 Updates

On Jan. 15, 2014, Casey Resources, Inc. submitted an Environmental Construction Report and Environmental Professional certification for the implementation of the VCUP. On behalf of the City of Boulder, Casey Resources, Inc. requested a No Action Determination for the subject site for its intended use for commercial/industrial purposes. On Feb. 24, 2014, the Colorado Department of Public Health & Environment (CDPHE) issued a No Action Determination Letter pdf approving the VCUP work completed to-date.

2013 Updates
Project completion was delayed approximately three months due to spring weather events. CDPHE granted an extension of the project schedule to December 2013.

2013 work included placement of a two-foot soil cap over the tailings pond and an additional 18-inch rock cap, stormwater drainage control, and site revegetation. Final documents were compiled and submitted to CDPHE for closure of the VCUP and any revisions to the environmental covenants required for the site.

As required by the Boulder County Limited Impact Land Use Review, within four months after CDPHE's revisions to the environmental covenants, the city will submit the mill site and the balance of the property for landmark designation with exclusions of specific areas deemed not to meet the Land Use Code's criteria for historic landmark designation. This designation will occur in fourth quarter 2013 (subject to change).

2012 Updates
Excavation and consolidation of contaminated soils at the primary tailings pond was completed in November 2012.

The Valmont Butte Remediation Project was included in the 2012 "Second and Final Budget Supplemental" request to City Council. The Second and Final Budget Supplemental is an annual budget adjustment meant to align the city's current budget with supplemental one-time line items that represent new budgeted amounts. The request included budget adjustments from across the city organization. Valmont Butte was one of the budget adjustments in the 2012 request.

In 2012, cleanup costs increased by about $1.4 million. The original cost estimate for the Valmont Butte remediation project was for $5 million; however, in any complex project, costs are first estimated and are likely to be adjusted as field work proceeds. In this case, the depth and width of contamination was estimated based on a comprehensive sampling program performed at 50- to 200-foot intervals, depending on soil quality results, but exact volumes could not be known until excavation occurred.

The largest single increase ($900,000) was not related to any increase in contaminated soil volumes or any other environmental condition, but instead was due to an increase in the volume of rock required to effectively deter prairie dogs. The actual volume of rock needed to reach the desired void space limitations was adjusted upward based on a field "test cap." There was no expansion of the cap footprint.

The other cost increases were spread across a number of items, such as asbestos abatement, prairie dog management, more extensive archeological monitoring, perimeter air monitoring, and additional oversight costs. Unanticipated asbestos abatement accounted for $77,000 of the increase. There was an increase in the amount of soil excavated, which accounts for approximately $180,000, and an associated increase in off-site fill material, which is estimated to cost approximately $230,000, to backfill excavation areas and supply clean soil cap material. The archeological monitoring costs increased $17,000 due to additional excavation inside the cultural area and documentation of potential artifacts in areas outside the excavation areas. (A final report from the archeologist will be available at the completion of the project.) Finally, some of these increases were attributable to the fact that the timeframe for completion has been extended by several months.

The city has an interim cost-sharing agreement with Honeywell (previous property owner) for 50 percent of construction and other site-related costs, with a right to seek reallocation in an arbitration hearing. The city's contribution is paid 50 percent from the General Fund, 40 percent from Utilities, and 10 percent from Open Space and Mountain Parks.

Legal fees, which are not part of the $6.4 million budget estimate, are attributable to negotiations with Honeywell, assisting in communications with CDPHE, and assisting in responding to public interest- related requests.

Even with the increase in costs, this approach to remediation is still much more cost-effective and certainly less disruptive to neighbors and the community than other options, such as removing all contaminated soil from the site to a licensed disposal facility.

Requests from other agencies to re-evaluate property status - May 2012

The United States Environmental Protection Agency (EPA) denied a petition by the Valmont School District No. 4 Cemetery Association and Rocky Mountain Peace and Justice Center to reevaluate the city's Valmont Butte property for federal Superfund consideration. (The city does not know precisely what the petitioners requested, as the city was not copied on the petition.) In addition, the Cemetery Association apparently raised similar concerns in an earlier letter (the city was not copied) to the Colorado Department of Public Health and Environment (CDPHE). Both the EPA and CDPHE responses confirm the regulators' continuing endorsement of the city's cleanup plan for Valmont Butte being implemented under the auspices of CDPHE's Voluntary Cleanup Program. Both agencies copied the city on their response letters and these have been added to this website:

The city will continue to be sensitive to the concerns of its neighbors at Valmont Butte as well as to the land and its history as the mitigation project continues. The city is committed to addressing environmental concerns on the site while preserving historic and cultural artifacts. These are responsibilities that the city takes seriously, and as such, qualified professionals have been hired to monitor the cleanup activities and assist the city in addressing these requirements.

Valmont Butte New Rock Feature - April 2012

Early in April, a new rock feature was discovered on the city's Valmont Butte site. After consulting with both the site's Native America monitor and the project archeologist, it was determined that this was not an historic rock feature and in fact, had been recently placed on the city's property without permission. The archeologist and Native American monitor helped the city dismantle the rocks on April 23, 2012.

Following the dismantling of this feature, the Sheriff's Office was called by the neighboring Cemetery, and an investigation was conducted to determine whether there was any crime involved in the removal of the rock formation. The Sheriff's Office determined that no crime was committed. See the Sheriff's Office report for more information.

The archeologist documented the rock feature and her conclusions about its lack of significance prior to its removal. Because of the interest by the public, the city is posting photographs and information from the archeologist's assessment.

The archeologist's report cannot be made public at this time. The report is part of a larger documentation effort of various materials identified on the Valmont Butte site in connection with site cleanup activities. Currently, this report is in draft form. When it is finalized, it likely will be submitted to the county as a confidential report. The reason for the confidentiality is so that locations of actual artifacts aren't inadvertently released to the public, which can attract thieves. Given these concerns, the city does not foresee releasing the full report in the future. However, the same photographic evidence of the rock feature found in April can be found in the assessment information currently available (see the related links section).

Settlements Reached

The City of Boulder, Honeywell International Inc. and Tusco, Inc. recently reached a settlement with the U.S. Department of Justice in the amount of $350,000, to resolve the U.S. Environmental Protection Agency's (EPA) costs for its past investigations at the Valmont Butte.

The Valmont Butte property, located at the intersection of 63rd Street and Valmont Road in Boulder County, is comprised of an abandoned ore milling complex and associated tailings ponds. The city purchased the property in 2000. In 2004 and 2005, the EPA investigated the site and prepared a site assessment report.

The City of Boulder also recently reached settlements with Honeywell and Tusco to resolve their liabilities as past owners and operators of the Valmont Butte mill site. Under those settlement agreements, Tusco's share will be $250,000 and the estimated costs for remediation are expected to be approximately $5 million, which will be split 50/50 between the City of Boulder and Honeywell, with the option to resolve the final damages in an abbreviated, mini-trial process. Honeywell will also be responsible for covering the EPA costs. More information about the settlements with Honeywell and Tusco can be found in an Information Packet memo that went to City Council in October 2011.

Board of County Commissioners Approves Applications - August 2011

In August 2011, the Board of County Commissioners conditionally approved the city's application for a Limited Impact Special Use Review for remediation work that will occur on Valmont Butte. The approval gives the city the authority to go ahead with remediation work on the site as long as some additional steps are taken to preserve specific historic buildings on site.

CDPHE Approves Remediation Plan - September 2010

The city received approval from the Colorado Department of Public Health and the Environment (CDPHE) in September 2010 for its remediation plan as part of the city's Voluntary Cleanup Plan (VCUP) application for the property. The project proposes to complete remediation of soils impacted with heavy metals and low-level, naturally occurring radioactive materials to limit the risk of human and wildlife exposure. The cleanup plan seeks to remediate the tailings pond areas as well as 14 additional areas outside the tailings ponds that were discovered to have high lead concentrations. The remediation strategy is driven by the need to construct a properly engineered cap on the primary tailings pond and the need to properly manage mining residuals located outside the tailings pond area. Contaminated soils will be consolidated in the tailings pond, and then covered by a new cap of soil and rock.