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Superfund during the COVID-19 pandemic

By Matt Vincent

Right now, everything is seemingly within the iron grip of the novel coronavirus/COVID-19 pandemic. Our daily lives have been redefined by the government’s response. As of Tuesday, April 15, Montana has 404 confirmed cases, 50 cumulative hospitalizations and seven deaths to the novel coronavirus.

Things here in Butte might not be so bad since our population is a lot less dense than most places, even for Montana. We are blessed to be able go outside and enjoy the fresh spring air and sunshine as long as we practice our social distancing and appropriate preventative practices.

One unique aspect of our lifestyle here that doesn’t directly affect other places is how we cope with Superfund. From the Berkeley Pit to the Warm Springs Ponds there are a number of vital management, monitoring and associated activities necessary in order to keep the public and environment safe. Although these activities are obviously affected too, many of them cannot simply be left undone until the current health crisis is over.

Luckily, environmental protection is on the list of essential activities needed to continue amid the pandemic. As such, it’s been business as usual – with some obvious adjustments and additional precautions – for the entities, agencies and individuals caring for our Superfund sites.

The first Superfund site that likely comes to people’s minds is the Berkeley Pit. Rest assured, the vital water monitoring, treatment and management activities that keep the Pit safe are ongoing. The Horseshoe Bend water treatment plant and the new polishing plant on Shields Avenue are both operating, the latter which continues to release millions of gallons of clean, treated water into Silver Bow Creek each day. Montana Resources, Atlantic Richfield Company and their contractors are working just as hard with a new diligence toward staying safe amid the COVID-19 crisis – for themselves, their coworkers and the community at large.

Keeping the “community at large” safe also applies to ducks and geese. Not only are the responsible parties continuing to manage and treat the groundwater filling the Pit, but efforts to protect the migrating waterfowl heading north are also in full effect.

Likewise, most of the activities at the other Butte area Superfund sites are continuing with additional precautions or are being done in part or are on hold due to the current crisis.

At the Montana Pole Plant, the remedy in place continues to operate as normal, which includes a water treatment plant to remove organic contamination out of the groundwater before releasing it into Silver Bow Creek. Water treatment activities as well as dam stability monitoring is also ongoing at the Warm Springs Ponds site.

On the Butte Priority Soils, the Residential Metals Abatement program continues to sample and clean up contaminated yards, while interior work on residences has been temporarily suspended. Inside work will start again once our public health agencies and the EPA determine it’s safe to do so.

Outside work evaluating and maintaining reclaimed mine dumps and stormwater controls also continues, as well as work operating and maintaining the Butte Treatment Lagoons, a system that manages and treats the contaminated groundwater coming from the Butte Hill and historic Silver Bow Creek corridor.

Meanwhile, public outreach activities are still taking place, although in-person forums and face-to-face interactions are currently on hold. The agencies and the parties involved, which include Butte-Silver Bow local government have turned to on-line and electronic means to help educate the community as well as to answer its questions, address its concerns and accept its input with respect to the pending Consent Decree for the final cleanup plan.

Of course, the EPA and the responsible parties are keeping a very close eye on the situation and are ready to revise these operations if new guidance is developed or if situations change. In the meantime, if a citizen has any questions, he or she may reach out to me at matt@rampart-solutions.com and I can do my best to help. Even better, coordinate with EPA Community Involvement Coordinator Dana Barnicoat at (406) 560-6261 or barnicoat.dana@epa.gov . Questions about local health concerns related to the pandemic should be directed to the Butte-Silver Bow Health Department at 497-5020.

Lastly – or maybe firstly! – thank you to all of the Superfund workers putting themselves out there during this tenuous time in order to keep our public health and environment safe. We truly appreciate your efforts!


A Fed Ex delivery truck and a semi-truck bringing lime to the Butte Treatment Lagoons are signs that the essential groundwater collection and treatment plant part of the Butte Priority Soils Superfund site is operating amid the COVID-19 pandemic. With specific adjustments and precautions in place, all activities necessary to keep the Butte area’s Superfund remedies functional are ongoing.[/caption]

Water discharged from Butte Mine Flooding site, Including the Berkeley Pit, for the First Time

By Tim Hilmo, Project Manager, Atlantic Richfield Company

With minimal headlines, treated water was discharged from the Butte Mine Flooding site to Silver Bow Creek for the first time starting on September 30, 2019.  Water from the Berkeley Pit is being treated at the Horseshoe Bend Water Treatment Plant, then the water helps convey Continental Mine mill tailings to the Yankee Doodle Tailings Impoundment.  Then water from the Yankee Doodle Tailings Impoundment is sent through miles of “gravity flow” pipelines to the new Polishing Facility located just east of Shields Avenue (adjacent to the Berkeley Pit viewing stand).  The Polishing Plant is staffed 24 hours a day to manage the water treatment processes and ensure the water treatment plant is operating as designed.  Once water is treated to meet the strict regulatory standards that apply to this plant, the water is discharged into Silver Bow Creek.  Water has been treated and discharged on an ongoing basis since September 30, 2019 at rates between 4-6 Million Gallons per Day (~6-9 Cubic Feet Per Second). In total through the end of January 2020, roughly 600 million gallons have been treated to the required standards and released so far. That’s over 900 Olympic sized swimming pools of water!

Atlantic Richfield Company constructed the Polishing Plant, in cooperation with Montana Resources, over the winter of 2018/2019, while Montana Resources constructed pump houses and installed piping to convey these waters around the site.  Construction was completed in September 2019 when system performance testing and treatment verification began.  Strict standards for metals concentrations, pH, and toxicity were established by the US EPA and Montana DEQ in the Butte Mine Flooding Consent Decree, to assure protection of surface water and aquatic life.  These requirements include daily compliance sampling of the treated water.  After a two week demonstration period of testing and agency review of the compliance sampling, approval was granted of the treatment process, and the much-awaited release of treated water to Silver Bow Creek began on September 30, 2019. For the first time in over 37 years, the water level in the Berkeley Pit is being controlled!

The treatment system is anticipated to operate for several more years as part of the ongoing Berkeley Pit and Discharge Pilot Project being implemented by Atlantic Richfield Company and Montana Resources under the Butte Mine Flooding Consent Decree.  Daily sampling will continue as a very close eye is kept on the quality of the treated water.


Berkeley Pit Polishing Plant



Restoring Butte: Environmental Education at the Berkeley Pit

By: Matt Vincent

The Berkeley Pit viewing stand ordinarily sees as many as 300 visitors each day when it’s open, making up for around 35,000 visits a year. A couple of weeks ago, there was one “out of the ordinary” new development at the viewing stand.

Members from the local citizens education group, PitWatch, and the Butte Chamber of Commerce decided to try something different for the festival season this year.

The tourists start coming into Butte in high gear in July. The busiest weekend of the summer is the Montana Folk Festival when tens of thousands of people flock to The Mining City to enjoy worldly arts, music and culture beneath our tall, iron headframes and historic buildings.

Mining and environmental cleanup are also vital and well-known parts of Butte’s present culture. Both are on full display at the Berkeley Pit viewing stand. Therefore, it shouldn’t come as a big surprise that many of these visitors end up going there to see the eye-catching blue-green, yet infamously contaminated waters of the Berkeley Pit.

There are plenty of hair-raising facts that people have heard about the Pit, leading to its ominous reputation – it’s nearly a thousand feet deep, holding close to 50 billion gallons of water contaminated from acid mine drainage. Birds have died from landing on and drinking the water, which will have to be treated “in perpetuity.”

But what about some of the newer facts? Much is going on recently at the Pit, so much so that it’s hard to keep up. For instance, did you know that since the last tragic bird die-off in 2016, scientists and managers at the Pit have successfully scared off and saved 99.8% of all birds that have landed?

Or how about this past spring? For the first time since the Pit began filling in 1982, water was pumped and treated out of the Pit at the same rate it’s coming into it, thanks to a new water management system constructed on site at the mine. Plus, later this year, once up and running properly, there is a newly constructed water polishing treatment plant that will be able to discharge clean water to Silver Bow Creek for the first time ever. These actions put the cleanup at the Pit four years ahead of schedule.

These are just some of the major changes being brought to bear on Butte’s Berkeley. And the people working on it and those charged with informing the public feel that more folks “out there” need to know.

In an effort to bring visitors up to speed, members from PitWatch and other subject matter “experts” working on the Superfund cleanup at the Pit were at the viewing stand on the Thursday, Friday and Saturday of this year’s folk festival to “show and tell” precisely about the past, present and future of the Pit and to accurately answer people’s questions.

At one point on Friday, scientists working on the Pit even flew a water-sampling drone in front of the viewing stand for visitors to see in action. This aerial drone technology is capable of taking water samples 200 feet below the surface of the Pit, while another drone boat constructed by researchers at Montana Tech can draw samples from over 600 feet deep.

These are a few more of the exciting new developments ongoing at what is arguably one of the nation’s most iconic Superfund sites. The media does its best to report on these developments, but with so many other stories and important topics to cover, it’s impossible to cover it all in depth. Even if the media could, it’s just as impossible to expect readers of the general public to find the time to keep up. It seems we’re always getting busier and busier, with no time to spare.

In the case of the Pit, catching a captive audience became the best approach. Over the nine hours that the viewing stand was specially staffed during the festival, over 600 visitors, young and old, from near and far asked dozens of Pit-related questions.

Everyone who came eventually left knowing lots more about Butte and the Pit than they ever did before. And the folks helping PitWatch learned some new things too – hanging out at the Pit and talking with people is a great way to educate them!

Feedback from many of the visitors, not to mention the experiences of the folks who helped out was so positive, there’s no doubt we’ll be doing it again – and maybe even more often!

You can also view this post at: rampart-solutions.com


Pitwatch.org Reimagined

I remember opening my first edition of PitWatch at my grandpa and grandma Lester’s dining room table as an 11-year old in 2002. The publication in those days was as fresh as it could be; it contained the latest water levels and flow updates, even breaking news about the then-upcoming Consent Decree. However, like many in our community, the edition left me with many questions. 11-year old Kayla’s mind raced. When did the pit begin filling? Who monitors this thing on a regular basis? Is someone watching this? Is it gonna flood? Why is it red? Are there fish in that thing?

My grandfather, Tom Lester, was a retiree from Montana Tech, surely he had answers for me. I looked at the edition number at the top of the PitWatch publication, and I remember asking “Grandpa, do you have all the old editions of PitWatch?” I was hungry for more information. Come to find out well, no, he didn’t have old editions. In fact, we were privileged to be getting the latest copy of PitWatch because it happened to be inserted into my grandparent’s subscription to The Montana Standard; and not everyone in Butte can afford a subscription to the newspaper my grandpa was happy to remind me.

Those editions of PitWatch left me feeling a little scared because I wanted to know as much as possible and I didn’t know where to go as a kid. Sure, I could have reached out to a committee member, but it was 2002, and I was 11. I didn’t have an email address or a cell-phone. The internet was “new” and little info about the Berkeley Pit existed online. I didn’t understand the updates found in a single edition of PitWatch. I wanted to see the background, the science, and the management of the Berkeley Pit as a full picture.  As little as 17-years ago, the average Butte community member did not have immediate access to the whole wealth of knowledge about the Berkeley Pit.

Flash forward to 2019, and we can now bring you the entire collection of knowledge, research, updates, history, and science behind the Berkeley Pit in one place. You can send us an email and get a reply in as little as a day! PitWatch.org is the only resource you will find that has been vetted by both scientists, industry professionals, AND most importantly, our own Butte community members.

As the communications coordinator for this website, I took it on as a personal challenge to help out those 11-year olds looking for all of the answers. I am blessed to work with a committee who has been in this business since before I was in Kindergarten. This committee is dedicated and committed to helping our community better understand the complexities of the Berkeley Pit. I welcome feedback on the website and want the information on found here to be as easily understood as possible. Please send a note to info@pitwatch.org if you have any questions or comments.

On a personal note – I’m not scared of this “thing” anymore. I feel empowered. I know this community can make a difference and I believe in our persistence, adaptability, and strength. If there is a city on earth who could be handed this type of card; it’s Butte. I believe in Butte and her people. And in case you are wondering; it’s not going to flood and spill into the city (scientifically impossible!) and, no, there aren’t fish in it!


Kayla Lappin (Lester)
Clark Fork Watershed Education Program (CFWEP) Communications and Events Coordinator
PitWatch Committee

This photo from July 2013 shows the rim of the Berkeley Pit were a slough deposited surface material into the Pit lake in Feb. 2013. Photo by Fritz Daily.

Snow Geese Update

• It is estimated that many thousands of migrating snow geese stopped in the Berkeley Pit the week of November 28, 2016. The number of migrating geese that passed through this area and landed in the Berkeley Pit is unprecedented. Most geese left the pit on Tuesday November 29, 2016 and continued their migration south.
• Unfortunately, some geese remained in the pit for nearly a week or longer, and it is estimated that several thousand of those snow geese perished in the Berkeley Pit.
• Montana Resources (MR) and Atlantic Richfield Company (AR) operate a program under the direction of US EPA and the State of Montana to deter waterfowl from landing in the pit, and to encourage any waterfowl in the pit to leave as soon as possible after resting. Over the course of the last two decades, the average number of birds observed on the Berkeley Pit over an entire year is approximately 4,000 or less, and almost all of those birds leave the pit after a short rest.
• On November 28, 2016, many more birds landed in the pit in one day than are normally seen over an entire year. MR and AR personnel attempted to convince the waterfowl to stay away from or leave the pit, using bird wailers, fireworks, and other conventional methods along with the addition of new technologies including drones. Staff diligence and dedication working day and night saved thousands of birds.
• MR and AR are coordinating with federal and state agencies, as well as waterfowl experts, to understand this unprecedented arrival of waterfowl in the Butte and why the waterfowl selected the Berkeley Pit for resting.
• MR and AR will work closely with federal and state regulators, and waterfowl experts to identify and evaluate potential new methods to strengthen and improve the waterfowl mitigation program. These may include such items as additional on-the-water and aerial remote control drone technologies, laser technology remote controlled water craft, and sonic devices.
• There is a program to provide veterinary care and assistance to sick geese. If members of the public in the Butte or Dillon areas spot a sick or dead goose, they are asked to please contact Montana Resources at 496-3233 or Butte-Silver Bow Animal Control at 406-497-6527.
• Montana, Fish, Wildlife and Parks (FWP) is advising hunters to wait to consume snow geese harvested after November 28 in the Butte and Dillon area. Instead, FWP recommends that hunters process and freeze birds at this time and do not eat them until the department has conducted tests to determine how or if this event has affected the edible portions of the birds.

This photo from July 2013 shows the rim of the Berkeley Pit were a slough deposited surface material into the Pit lake in Feb. 2013. Photo by Fritz Daily.

Study details slope stability

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.

This photo from July 2013 shows the rim of the Berkeley Pit were a slough deposited surface material into the Pit lake in Feb. 2013. Photo by Fritz Daily.
This photo from July 2013 shows the rim of the Berkeley Pit were a slough deposited surface material into the Pit lake in Feb. 2013. Photo by Fritz Daily.

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.

This September 2014 photo from Google Earth shows the Berkeley Pit and the surrounding area.

Water level rising more slowly than originally projected

This September 2014 photo from Google Earth shows the Berkeley Pit and the surrounding area.
Click on the image to view a larger version.

Since the Berkeley Pit was designated as a Superfund site in the 1980s, things have gone largely as expected. In one instance the site remedy has proceeded at a faster pace than mandated in the 1994 Record of Decision (or ROD, available in its entirety here).

The ROD called for the water treatment plant for the Pit to be designed 8 years before the water level at any monitoring compliance point reached the Critical Level of 5,410 feet above sea level, and completed 4 years prior. In fact, the Horseshoe Bend Water Treatment Plant was completed in 2003, 20 years before water is expected to reach the Critical Level.

Water level modeling has also been accurate. The Pit water level has risen more slowly than originally predicted due to several factors, most notably the capture and treatment of contaminated surface water flowing in from Horseshoe Bend. This water is treated and reused in Montana Resources mining operations, with no water discharged offsite.

The 1994 ROD included projections that estimated that the water level in the Pit would be at 5,204 feet above sea level in 2000; 5,353 feet in 2010; and 5,417 feet in 2015. With a water level of just 5,326.01 feet recorded on August 5, 2015, the Pit water level is nearly 100 feet below early predictions.

The 1994 model also anticipated a rate of fill of about 5-6 million gallons per day. With surface inflow captured, treated, and reused, the average rate has been much lower, about 2.6 million gallons per day. The model currently used by the Bureau of Mines and Geology uses monitoring data to project the filling rate, and over the past 5 years the model’s projections have varied by only a few months.

Some surprises have occurred over the years. For example, the 1994 ROD projected that the water level in the Anselmo mineshaft would be the highest in the Pit system. That was the case until the past several years, when the water level in the Pilot Butte shaft overtook it. Since then the highest water level is typically recorded at the Pilot Butte mine, which was at 5,351.11 as of August 5, 2015.

At 58.89 feet below the Critical Level, it is likely that the Pilot Butte water will hit the critical point first, triggering full implementation of the Horseshoe Bend Water Treatment Plant. This is currently projected to happen in July 2023, a few months later than projected in the last edition of Pit Watch in 2013.

Due to safety concerns related to landslides (or sloughs) along the Pit rim, the Montana Bureau of Mines and Geology has not taken this research boat out on the Pit lake for water quality sampling since 2012.

Drones in the works for water quality sampling

Montana Resources and Atlantic Richfield are currently funding a Montana Tech graduate student to develop a remote system to sample Pit water quality. The student will review options to collect the required data, including aerial or water-based drones that can be operated from the shore of the Pit.

Due to the size of the Pit and the need to collect samples from locations throughout it, the ability to communicate with the drone at a distance of up to 2 miles is essential. Work began during the summer of 2015 and will continue through the 2015-2016 academic year and summer 2016, with final testing during the June and July, and collection of Pit samples by August 2016.

Electrical engineering assistant professor Bryce Hill is supervising the project. He said the device could potentially be used for applications beyond the Berkeley Pit.

Read more on the project from The Montana Standard.

Due to safety concerns related to landslides (or sloughs) along the Pit rim, the Montana Bureau of Mines and Geology has not taken this research boat out on the Pit lake for water quality sampling since 2012.
Due to safety concerns related to landslides (or sloughs) along the Pit rim, the Montana Bureau of Mines and Geology has not taken this research boat out on the Pit lake for water quality sampling since 2012.
Projected Berkeley Pit management timeline (2015-2023).

Plan for treatment technology assessment

The guiding documents for Pit management require ongoing assessment and evaluation of the Horseshoe Bend Water Treatment Plant and the technology used to treat contaminated Pit water until several years prior to full-scale implementation. That implementation is required when water levels at any monitoring compliance point reach the Critical Level of 5,410 feet above sea level.

A review of treatment technologies is required 4 years before any compliance point is projected to reach the Critical Level. Current projections show that the Critical Level will be reached in 2023; therefore the technology review will start in 2017 and must be completed by 2019. AR and Montana Resources are already evaluating treatment alternatives, and this work will continue through 2017. This includes treatability studies and testing on the expected quantity and quality of contaminated water. Construction upgrades are scheduled for 2019 through 2021, with upgrades completed at least 2 years before the Critical Level is reached.

Projected Berkeley Pit management timeline (2015-2023) and significant past events.
Projected Berkeley Pit management timeline (2015-2023) and significant past events. Click on the image to view a larger version.
A piece of gypsum ‘scale’ removed from the Horseshoe Bend Water Treatment Plant.

Following up on the EPA’s 2010 five-year review

In 2010 EPA interviewed local citizens and reviewed the status of Butte area Superfund sites as part of a required five-year review (the full review report is available here). Five-year reviews determine whether remedies or other response actions are protective of human health and the environment in compliance with a site’s decision documents. Methods, findings, and conclusions are documented in five-year review reports that identify issues found and make recommendations to address them.

The 2010 review identified six main issues related to the Butte Mine Flooding Operable Unit (BMFOU), which includes the Berkeley Pit. All involved the performance of the Horseshoe Bend Water Treatment Plant, which was completed in 2003.

The plant currently treats contaminated surface water flowing in from the north. This water is diverted away from the Pit, slowing the rate of rise of the water. Eventually, when the water level at any compliance point reaches the Critical Level of 5,410 feet, the plant will pump-and-treat Pit water to keep levels below that critical point. A performance test was conducted at the plant in 2007, and that data was considered in the 2010 review.

All treated water is currently recycled to Montana Resources active mining operations and is not discharged to Silver Bow Creek or any other surface outlet, Consequently, EPA identified all issues in the review as potential future issues that do not effect the current protectiveness of the remedy. Montana Resources does not allow any water to discharge from the Berkeley Pit and active mine area.

Issue 1: pH

Water treated at the plant did not meet the final pH standard. pH measures the acidity of a liquid. The pH is purposely raised to over 10 in order for it to be used as operating water in Montana Resource’s mill. Discharge standards only apply when water is discharged to Silver Bow Creek.

Issue 2: Gypsum scaling

Gypsum scale build up on the lip of the treatment plant clarifier overflow.
This photo from EPA’s 2010 five-year review report shows gypsum scale build up on the lip of the treatment plant clarifier overflow.

During the water treatment process, gypsum sometimes builds up, or ‘scales’, on the inside of tanks and pipes. This leads to a need for additional maintenance, as parts of the plant must be shut down for a short period each year so that crews can remove the build up. Measures to help manage and reduce scaling are being evaluated, and gypsum concentrations are monitored weekly.

Issue 3: Cadmium

Testing showed that treated water at times did not meet the standard for cadmium, a toxic metal. After adjustments were made to increase the pH, the standard for cadmium was met.

Issue 4: Test did not include treatment of Pit water

The 2007 performance test measured treated surface water from Horseshoe Bend. While this water is similarly contaminated, Pit water has higher concentrations of toxic metals and sulfate.

Issue 5: Scale Inhibitors used to control gypsum may effect metals removal

This issue is closely related to issue 2. To reduce gypsum scaling on critical pipelines and pumps, scale inhibitors are used. These chemical additions make it more difficult for gypsum to precipitate out of treated water and build up in the plant. Their effect on metals removal was a concern, but studies have shown no discernable effect of inhibitors on metals removal.

Issue 6: Whole Effluent Toxicity

Whole Effluent Toxicity (WET) is a measure of the total toxic effect from pollutants in treated wastewater on aquatic life. In 2010, WET testing had not yet been performed on treated water. Treated water is currently recycled in active mining operations, so it is no threat to aquatic life. Preliminary WET testing was completed during pilot testing using Horseshoe Bend water. Results showed the chronic exposure concentration with the lowest observable effect was 75% treated water mixed with 25% dilution water. More WET testing is planned.


EPA recommended that an additional performance test be completed prior to the 2015 five-year review to investigate all six of these issues and possible solutions.

EPA also noted that operations and maintenance at the plant are now more focused on preventative care, and operations in general have been optimized. After adjustments, treated water met all discharge standards with the exception of pH (issue 1).

In order to be protective in the long term, the various water quality issues in treated Pit water will have to be resolved before discharge to Silver Bow Creek becomes necessary. As long as Montana Resources continues active mining at the Continental Pit, no discharge is expected to occur.

Recommendations for additional performance testing will be addressed by treatability studies starting in 2016 and concluded by 2019, well before any discharge would potentially occur.

EPA determined that the ongoing remedy for the Pit is functioning as intended. When the water approaches the Critical Level, additional testing will help to further refine plant performance. The 2015 five-year review of Butte area Superfund sites will be published later in 2015, and will be available online here and on the EPA’s Butte Superfund website.

Interested citizens should contact EPA with any questions or comments regarding the 2010 or 2015 site reviews.