| Clean Up Options |
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How does EPA evaluate options? There are nine EPA evaluation criteria applied to any possible cleanup option. The first two of these criteria have absolute weight, meaning that the others are considered only after these first two have been met. Threshold Criteria (must be met). * Overall protection of human health and the environment - must attain level of protectiveness. * Compliance with state and federal standards and regulations. Where impossible to meet, a waiver may be considered. Balancing Criteria (must be considered). * Long-term effectiveness and permanence of the remedy * Reduction of toxicity, mobility and volume * Short-term effectiveness * Implementability (Is the remedy doable?) * Capital, operating and maintenance costs Modifying Criteria (must also be considered). * State acceptance (acceptance of the plan by state officials and government leaders) * Community acceptance (What do residents in the immediate area want done with the river?) What cleanup options are currently being studied? The options listed below are taken from the working feasibility studies for both the Milltown and Upper River sites. The official options will be released to the public most likely in October and November. Check back for finalized options. Milltown Site Currently, EPA is looking at 10 options for cleanup (seven main options and three sub-options). Since the feasibility study has not been officially released for public comment, the 10 options have been scored on the first seven of the nine evaluation criteria EPA considers. Two of the options scored high in the initial phase of EPA's review. One of these two options is most likely to be the chosen solution. Which is chosen will depend at least in part on state and local acceptance (criteria 8 and 9). Option 2. Under this cleanup option all sediments and the dam would remain in place. The dam would be upgraded for safety, a fish passage would be added, and an inflatable rubber dam would be installed (to aid in passing ice over the dam during an ice event like the one in 1996). In addition, operational practices at the dam would be modified to reduce sediment flow downstream. Implementing institutional groundwater controls, such as closing wells and preventing access to tainted water, would be applied to the arsenic plume in the groundwater, and the replacement water supply for local residents would be maintained. Option 2 scored well for short-term effectiveness, cost and implementability. It is the option favored by Arco, The Montana Power Company and Bonner Development Group. This option is estimated to cost $20,654,000. Option 7A. Under this cleanup option, the sediments and the dam would be removed. All sediments in the channels of the lower reservoir would be removed, and all sediments in the floodplain below Duck Bridge would be removed. To do this, the reservoir would be reduced to less than half its current size. Exposed sediments (estimated to be 50 to 70 percent of the total sediments to be removed) would be dry excavated with traditional excavation equipment. The remainder of the sediments (those lying in the channel) would be dredged, most likely with a cutterhead suction dredge and silt curtains to mitigate downstream impacts from dredging. All sediments would be deposited in a safe repository and treated in perpetuity. Once sediment removal is complete (an estimated three to seven years) the dam would be dismantled and some form of rechannelization work to restore the natural confluence of the Blackfoot and Clark Fork rivers would move forward. The groundwater arsenic plume would be treated as in Option 2 above, but in addition, the removal of the source of the contamination would eventually diminish and clean the existing tainted groundwater plume. As with all other options, the replacement water supply would be maintained. Option 7A scored well for long-term effectiveness and permanence of the solution. It would however, cost Arco about $100 million more than would Option 2, and it would impact aquatic life downstream in the short term. Option 7A is favored by the greater Missoula community including both businesses and individuals; the Missoula County Commissioners; the City/County Health Department, the Fishing Outfitters Association of Montana; Montana Fish, Wildlife and Parks; and environmental groups such as the Clark Fork Coalition. It is also the remedy favored by the Clark Fork Technical Assistance Committee board of directors, based on our review of scientific reports from all parties. This option is estimated to cost $120,825,000. Upper River Site EPA is still working with Arco to finalize and clarify the options for cleanup in the upper river. Generally speaking, however, there are two main cleanup methods that may be used, wholly or in conjunction with one another. Removal of slickens and metals deposits from the bank and floodplain. Slickens are large deposits of contaminated soils on which virtually no vegetation will grow. They exist in many areas along the upper river. Removing these slickens and other contaminated soils would be a complex and costly remedy, but it would replace all or most of the contaminated soils along the upper Clark Fork with clean soil. These areas would be revegetated to stabilize the banks. Treatment of slickens and metals deposits in the bank and floodplain. This would be a less costly remedy, whereby lime would be plowed into the contaminated soils to neutralize them. The areas would then be planted with vegetation to help reduce erosion of the contaminated soil into the river. It's important to note that this method does not render the sediments harmless, it simply controls erosion into the river. Please check back to learn more about cleanup options on the upper river, as information becomes available, or joint our listserve to be notified of updates. Who pays for the cleanup? The estimated cost breakdown for the cleanup options at Milltown is as follows. No numbers have been made available for the upper river. Option 1: No further action $17,719,000 Option 2: Modification of dam and operational practices $20,654,000 Option 3a: #2 with erosion/scour protection $52,127,000 Option 3b: #2 with channelization $73,117,000 Option 4: #2 with periodic sediment removal $59,866,000 Option 5: Dam removal, partial sediment removal (lower reservoir) with channelization, leachate collection/treatment $121,469,000 Option 6a: Modification of dam and operational practices with total sediment removal (lower reservoir area) $117,475,000 Option 6b: Modification of dam and operational practices with total sediment removal (total reservoir area) $190,696,000 Option 7a: Dam and sediment removal (lower reservoir area) $120,825,000 Option 7b: Dam and total sediment removal (entire reservoir area) $201,813,000 Regardless of the option chosen, the responsible party, in this case Arco (a division of British Petroleum), would pay for the majority of the cleanup. If it's determined that Milltown Dam will be removed, The Montana Power Company may be responsible for some of the removal cost. After the cleanup, restorative solutions, for example the proposed Two Rivers Restoration Project, would be funded from other sources. What would be the impacts of a cleanup? As with any cleanup, there will be impacts, both negative and positive. While EPA only considers human health and environmental impacts in its decision, we've outlined some other impacts about which citizens have stated concern. Human health impacts: All of the options being considered meet the requirements for adequately safeguarding human health. However, only the options that favor removal of sediments have the potential to actually clean up the groundwater plume (the biggest immediate threat to human health) because the contamination source would be removed. There is also the threat (albeit very small) of catastrophic dam failure. This potential can be reduced through the safety changes proposed in Option 2 and required by FERC. Removing the dam and sediments, as laid out in Option 7A, would completely eliminate the threat. Fishery Impacts: According to most studies, the removal options are the best long-term solutions for aquatic health because they eliminate the source of contamination, and, in the case of Milltown, they would remove a barrier to native fish migration (the dam) and the shallow warm reservoir inhabited by non-native pike. Removal also eliminates the risk for fish kills caused by high water events and ice scouring. In the short term, removal would slightly increase the impact on the fishery due to the mobilization of copper during dredging. On the other hand, the best short-term and least costly remedies are those that stress treatment rather than removal. These would have little if any short-term impact on aquatic life, however, they also do little to improve fish populations and health long term. And the risk for large fish kills during high-water events would remain. Missoulian dredging article EPA Fact Sheet Channelization Impacts: During remediation and before revegetation, the channels in the upper river would be somewhat more susceptible to erosion. This can be mitigated by following Best Management Practices, but should a serious flood occur during sediment removal or before revegetation, fish kills could be extremely high in the upper river, and toxic sediments could be completely relocated. It's important to note that even if no course of action is followed on the upper river, flood conditions would have similar impacts on aquatic life as metals were eroded into the river. Economic Impacts: As a general rule the costlier cleanup options have the largest economic impacts - negative for Arco and positive for local economies. Total removal and cleanup would create many more, longer-term jobs in the area than less work-intensive options. At this time, there are no solid estimates for job numbers or overall economic impact by option. Once a plan is proposed, these numbers would be calculated and released. Removing the dam does create a negative economic impact on the local Bonner School District, because it would eliminate the tax earned from the dam each year. Proposals have been offered to help offset this loss of tax revenue, but they are outside the scope of EPA's responsibility. Landowner Impacts: Impacts to landowners would be greatest along the upper river. These impacts include allowing access for cleanup and the short-term loss of some production on land in the riparian zone and floodplain. In most Superfund cases, landowners can be financially compensated for such losses. It is unknown what the long-term liability issues might be for landowners if Arco is allowed to leave sediments in place. The sediments may no longer be Arco's responsibility after the process is complete. For example, if a flood washed sediments off your land and onto your neighbor's, would you be responsible for his loss or for cleanup? While this description greatly simplifies the actual issues and potential questions, it's indicative of the kinds of issues that will need to be resolved. The public should convey its concerns about landowner liability and other concerns to EPA and the State. Energy Impacts: Removing the dam at Milltown takes, on average, 1.5 megawatts of power off the Montana grid annually. While no amount of electricity is minor, it's important to note that removing Milltown Dam won't send us into an energy crisis. 1.5 megawatts is less than one percent of what Montanans consume each year. With available technology is a safe cleanup possible? Yes. While any cleanup will have some short-term impacts, all considered options will be doable without threatening public safety, or to any great extent, aquatic health. Who supports which options? CFRTAC will be posting positions by various organizations throughout Montana. We have contacted the parties directly involved in the Superfund process and we plan to post more positions soon. All positions will be written by the party named and posted as they are provided to CFRTAC. If you would like your group's position posted here, please send us an e-mail. CLARK FORK COALITION MISSOULA CITY-COUNTY HEALTH DEPARTMENT FISHING OUTFITTERS ASSOCIATION OF MONTANA MISSOULA COUNTY COMMISSIONERS MISSOULA CITY COUNCIL POSITION MONTANA FISHING OUTFITTERS CONSERVATION FUND MONTANA TROUT UNLIMITED EPA Fact Sheet on cleanup options |
