The rate of rise of water levels in the Berkeley Pit and connected monitoring points is affected by many factors, including rain and snowfall and occasional ‘sloughs’ or ‘slumps’ of material from the Pit’s sidewall slopes.
The most recent slough occurred on February 8, 2013. An estimated 820,000 tons of material from the southeast wall collapsed into the Pit. Montana Bureau of Mines and Geology (MBMG) monitoring showed that the water rose about 0.6 feet as a result. For comparison, over the past several years the water has risen about 0.65 feet per month.
Sloughs or landslides are relatively common in open pit mines and can potentially raise water levels. To address the potential effects of future sloughs on the Pit’s rate of rise, EPA required the Potentially Responsible Parties (PRPs) for the site, Montana Resources and the Atlantic Richfield Company (AR), to study the stability of the slopes around the rim of the Berkeley. Publication of the final report on that study is expected later in 2015, and it will be published here on the PitWatch website.
EPA and the PRPs have stated that preliminary results indicate that the rising Pit water level will continue to increase the potential for slope failure, especially in the southeastern part of the Pit. Future sloughs are expected to occur in the absence of any stabilization or mitigation measures, but, based on past sloughs, are not expected to significantly affect the Pit management timeline.
Two much smaller landslides, which had no noticeable impact on the water level, occurred in August and November 2012. A larger landslide occurred in 1998. The November 2012 slide damaged the Montana Resources pontoon boat used for water quality sampling in the Pit. Following the 2013 slide, those sampling activities were suspended for the safety of the MBMG scientists who conduct the sampling.
Butte has the dubious distinction of being at the upper end of the largest complex of federal Superfund sites in the U.S. This Superfund complex extends from Butte and Anaconda 120 miles down the Clark Fork River to Missoula.
The word “Superfund” is tossed around a lot by local and state officials working in the Clark Fork Basin, but, to the average citizen of western Montana, the term might not mean very much. Nevertheless, Superfund is changing the landscape of western Montana, from the Berkeley Pit to the Anaconda Smelter all the way downstream to the former Milltown Dam.
In simple terms, Superfund refers to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980. This federal law, passed in the wake of environmental disasters like Love Canal, was designed to clean up abandoned hazardous waste sites that may endanger public health or the environment.
The law authorizes the Environmental Protection Agency (EPA) to identify parties responsible for contamination of sites and compel the parties to clean up the sites. Where responsible parties cannot be found, EPA is authorized to clean up sites itself using federal funding.
The Superfund cleanup process is very complex. It involves the steps taken to assess sites, place them on the National Priorities List, and establish and implement appropriate cleanup plans. This is the long-term cleanup process. EPA also has the authority to remove hazardous wastes where immediate action needs to be taken; to enforce against potentially responsible parties; to ensure community involvement; to involve states; and ensure long-term protection.
According to the EPA, as of August 5, 2013 there are 1,320 sites listed on the National Priority List, an additional 365 have been delisted, and 54 new sites have been proposed. There are currently 17 National Priority List sites in Montana, and two Superfund sites that are not part of the National Priority List.
Under a clear EPA order, both Montana Resources and BP-ARCO are responsible for treating Berkeley Pit water. Under the Superfund law, if one company is unable to pay its share, the other company must pay all the costs of cleanup. The company paying the full cleanup costs would likely take some legal actions to recover a fair share of those costs from the other company.live streaming film Buster’s Mal Heart online
An operable unit is a subsection of a larger EPA Federal Superfund site. There are four Operable Units (OUs) in the Butte mining district.
The Butte Mine Flooding Operable Unit, which includes the Berkeley Pit, the hydraulically-connected underground mine workings associated with the historic East Camp and West Camp tunnel systems, associated bedrock, and alluvial aquifers. The area covers approximately 23 square miles.
Butte Priority Soils is a five square mile area that includes the town of Walkerville, along with the part of the Butte Hill that is north of Silver Bow Creek, west of the Berkeley Pit, and east of Big Butte. It also includes a section of land extending south from Silver Bow Creek to Timber Butte. This Operable Unit includes residential yards, mine dumps, contaminated railroad beds, and stormwater drainages on the Butte Hill and in Walkerville.
Silver Bow Creek/Streamside Tailings Operable Unit, which follows Silver Bow Creek from just below the historic Colorado Tailings deposit in Butte and 25 miles downstream to the Warm Springs Ponds. The area includes Silver Bow Creek itself, as well as the adjacent mining wastes deposited along the creek bank and nearby floodplain, and railroad embankments adjacent to the stream that contain mining wastes.
West Side Soils Operable Unit includes lands that fall outside of the Butte Priority Soils OU. There are approximately 1,500 mine waste dumps located north and west of Butte. The dumps have not been sampled. A schedule for investigating this OU and selecting a remedy has not yet been set.
There are numerous additional operable units in the greater Clark Fork River Superfund site, which stretches from Butte and 120 miles downstream to the Milltown Dam near Missoula.
There are two reasons why the Pit will never overflow. First, the 1994 Record of Decision and 2002 Consent Decree established the maximum level that the water will be allowed to reach to make sure the Berkeley Pit is lowest point in the cone of depression (see center graphic). Wells to monitor water levels have been set up. Failure to keep the water below the 5410′ elevation would result in steep fines for BP/Atlantic Richfield and Montana Resources. Second, the Horseshoe Bend Water Treatment Plant is already in-place and operating. It has the capacity (7 Million Gallons per Day) to treat water from the Berkeley Pit, when it becomes necessary. This will ensure the water level remains below 5,410′.
The Horseshoe Bend Water Treatment Plant will empty the Berkeley Pit.
In the 1994 Record of Decision, the agencies decided that it would be unfeasible for the Potentially Responsible Parties (PRP’s) to ever completely empty the Berkeley Pit. The remedy selected for the Berkeley Pit is to treat all water inflows to maintain the level below 5,410′ above sea level.
Congress is cutting the national Superfund program and the operation of the Horseshoe Bend Water treatment Plant will be discontinued.
The ‘Butte Mine Flooding Superfund Site’ is the responsibility of BP/Atlantic Richfield and Montana Resources. Thus, the plant will not be affected by any changes to the EPA’s Superfund Program. The legally binding Consent Decree, which was signed by the responsible parties in 2002, established the financial commitment to operate and maintain the water treatment plant in perpetuity.
When the Horseshoe Bend Water Treatment Plant starts operating later this year, the contaminated waters from the Berkeley Pit and underground mines should be managed safely for years to come. In the meantime, another cleanup project – called the Butte Priority Soils Operable Unit – is just now reaching its critical decision point (i.e., the Record of Decision, scheduled by the end of 2003). Over the next several months, there will be a series of public meetings about this project, and the Committee would like to share information to help citizens understand the issues and encourage participation in the decision-making process.
Where is the Butte Priority Soils cleanup site?
Generally, the project includes the residential yards and mine dumps on the Butte Hill and in Walkerville, and the water drainages weaving down the Hill to Silver Bow Creek. The site is about five square miles and includes most of the urban area from Walkerville on the north to Silver Bow Creek on the south, along with the Clark Tailings below Timber Butte.
It’s also important to understand what the Priority Soils does NOT include. It’s separate from the Berkeley Pit and underground mine flooding project, which, as we’ve reported in PITWATCH for several years, is the responsibility of Arco and Montana Resources. The Priority Soils is also separate from the Montana Pole cleanup and the Streamside Tailings project along Silver Bow Creek, both of which are ongoing and the responsibility of Montana Department of Environmental Quality. In the big picture, all these cleanup activities will have to fit together, but for now, Priority Soils stands alone.
What is the cleanup task?
The job is two-fold:
to eliminate direct contact with mine waste on the Hill, thus protecting human health; and
to prevent the heavy metals in those mine waste materials from getting into storm water and groundwater and finding their way to Silver Bow Creek, thereby protecting life in the stream and the DEQ’s $85 million creek cleanup project.
Is some work already complete?
Yes. In fact, a substantial amount of the cleanup of Priority Soils has occurred – about $50 million of work by current estimates. Over the past 15 years, several projects have been completed, with the understanding that all this work will be reviewed as part of the final decision. Major projects include: the Alice Pit/Dump (1998); several areas in Walkerville (1988, 1994, 2002); the Missoula Gulch, Buffalo Gulch and Kelley ditches and retention ponds (1997-99); railroad corridors (2001-03); and Lower Area One, including the reconstructed Silver Bow Creek, the Colorado Tailings removal, and the Clark Tailings project (1993-2000).
In all, more than 175 mine dumps covering more than 400 acres have been partially removed and capped, and more than 180 residential yards have been cleaned up (lead soil removals). The caps generally consist of placing 18″ of clean soil materials with organic amendments over the wastes and planting native vegetation to hold the soil in place and minimize erosion. To complement the caps, a system of storm water collection facilities – the new drainage ditches and retention ponds – has been installed to collect water that may still contain heavy metals and prevent those contaminants from reaching Silver Bow Creek.
What Other Areas and Issues Must Be Addressed?
The major cleanups still ahead include the Parrot Tailings near the Civic Center and the Metro Storm Drain corridor, which once was the historic Silver Bow Creek channel that flowed through town, and a large area north of the Kelley Mine, surrounding the Mountain Con Mineyard and the Granite Mountain Memorial.
In addition to cleanups, other issues include deciding what type of water treatment system should be used to ensure groundwater, surface water or storm water leaving the area will not pollute Silver Bow Creek heading west of town. Another big decision will be to determine whether the projects already completed were done satisfactorily and will be permanent, or whether additional work is needed.
Perhaps the most important issue is to determine how the reclaimed areas and water management facilities will perform in the long term and be effectively maintained. As part of the Record of Decision, it will be critical to set the right performance standards for treatment and long-term care, and then determine how much money it will take to get the job done properly.
Is Butte on the hook for the Priority Soils cleanup?
Unlike every other cleanup around Butte, where the citizens have been protected from any Superfund liability, Butte-Silver Bow was named as a Potentially Responsible Party or PRP to conduct the Priority Soils cleanup. In 1990, EPA decided that since the publicly owned storm water system carried wastes off the Hill to the creek, the community was partly liable for the problem.
However, Arco is also a PRP for Priority Soils, and for the most part over the past 15 years, Arco has paid all costs for cleanup work. As part of the upcoming Record of Decision and then a Consent Decree for the Priority Soils project, Butte’s “share” will be determined.
In March 2002, the Atlantic Richfield Company (ARCO) and Montana Resources (MR) agreed to sign a Consent Decree, a legally binding document that will be entered in federal court. The Consent Decree requires these companies to reimburse EPA and DEQ for past costs, and pay now for future oversight costs. It also guarantees that these companies will perform a number of tasks and provide financial assurances to pay all costs to complete the required work.
Most importantly, the Consent Decree sets a firm schedule for Arco and MR to build a water treatment facility, and confirms their obligations to operate and maintain the facility – including sludge disposal – in perpetuity. Also included in the Consent Decree are commitments to enhance the waterfowl protection program at the Berkeley Pit, to establish a groundwater control area surrounding the Berkeley, to fund the Montana Bureau of Mines and Geology (through the EPA and DEQ) to continue the mine flooding monitoring program, and to fund public education activities (e.g., PITWATCH).
As part of the process, ten changes were made to the Record of Decision (1994). For example, changes were made to recognize new stream and discharge standards for the treated water, to allow Continental Pit water treatment in the Horseshoe Bend plant, and to allow sludge disposal in the Berkeley Pit. Another change eliminates the requirement to reevaluate treatment technologies when the water level in the Pit reaches the 5,260′ level, since the treatment plant will already be built. The Consent Decree also clarifies which cleanup tasks will be done under the Superfund program and which will be done under the State’s active mine permit reclamation program.
The Consent Decree was released on March 26, 2002 for public comment until May 4, and is expected to be finalized thereafter. Contact the Committee with any questions.