Skip to main content

Adaptive Management Plan, 2006

According to the mine’s original Adaptive Management Plan (AMP), the water quality problems at the mine should trigger specific actions. The steps are clearly outlined, requiring the company to: notify Ecology, identify the source of the contaminants and the extent of the plume, and develop a plan to remediate the problem. Over the years, various levels of investigation have provided useful data to help in the search for the contaminant flow path. Likely culprits have been identified, such as surface water from mine facilities, development rock stockpiles, and the underground mine workings. Collecting monitoring data in the appropriate locations, such as below the development rock stockpile, is critical to understanding the source of the water quality problems.

Phases of Adaptive Management

Adaptive Management details include an action threshold and indicate who would take what action. The specific plans have three phases:

  • Phase I (early action) based on 50% of predicted impact: Kinross would review data and determine the likelihood predicted impacts would be exceeded. If they think there would be a potential for greater impacts they would inform the agency in their annual report. Take voluntary action and continue monitoring. The agency would take no action.
  • Phase II (planning) based on 80% of predicted impact: If Kinross decides monitoring suggests impacts would exceed predictions, they would then develop a Contingency Plan. The agency would meet with Kinross and develop a plan.
  • Phase III based on 100% of predicted impact: Kinross would implement Contingency Plan. The agency would oversee contingency actions.

Below are examples from the Adaptive Management Plan, stating what actions will be taken if water quality data show parameters exceeding background values. Although levels have exceeded background since mining began, these adaptive management steps have not been followed.

AMP excerpt regarding water quality exceeding background levels (click to enlarge)
AMP excerpt regarding the capture zone (click to enlarge)
Ongoing AMP Issues
Kettle River Tailings Facility

There was a trend of increasing concentrations of nitrate, sulfate, and TDS in surface water; this should require Adaptive Management Plan action.

Issues with the Supplemental Environmental Impact Statement AMP

One of the major flaws in Ecology’s Supplemental Environmental Impact Statement (SEIS) was its reliance on adaptive management or more accurately a plan that is titled adaptive management but in reality has poor mechanism to adapt to changing situations. It would be more accurately be characterized as a monitoring plan. Adaptive management should be an active systematic process for continually improving management policies and practices by sequential learning from the outcomes of operational programs. It should be designed to experimentally compare selective policies or practices by evaluating alternative hypotheses. Ecology and Kinross want to redefine adaptive management and use it as a basis for the entire mine plan.

To put this plan in perspective, Ecology relied on this adaptive management plan for most aspects of the mine proposal including:

  • Dewatering impacts to seeps and springs
  • Dewatering and water supply impacts to steamflow
  • Fine sediment deposition and water quality changes to Marias Creek from the mine access road
  • Aquatic habitat improvements to mitigate for streamflow impacts from mine dewatering
  • Development rock management
  • Water treatment plant operations
  • Upland habitat protection, enhancement and management
  • Wildlife management along haul road
  • Kettle river tailings impoundment

The AMP was relied on to evaluate the monitoring data and compare it to what is predicted in the SEIS and to evaluate compliance to the requirements of various permits including:

  • The NPDES for the collection, treatment and discharge of mine water,
  • The water rights for the use of surface water and ground water supply and mitigation,
  • The construction and operational stormwater,
  • The hydraulic permit approval for the construction and maintenance new culverts and stream restoration,
  • The permits on National Forest Land,
  • The waste discharge and Dam Safety for the tailings impoundment

Water Rights for the Mine

Background

Water Rights were historically OHA’s main vehicle for protecting surface water. Ecology took the position that since Washington State Water Law requires that water be put to beneficial use in order to get a water right, that if water is not being put to beneficial use, a water right is not required. This absurd interpretation of water law created a loophole that allowed Kinross to dewater Buckhorn Mountain and dump the water.

OHA’s Initial Concerns in the Mine’s Planning:

The dewatering of Buckhorn Mountain would be the most damaging aspects of the proposed mine. Ecology approved for Kinross to extract all the water from Buckhorn Mountain’s heart of gold. In order to mine, people, fish, and wildlife would be deprived of clean water. In some creeks, clean water would be replaced with treated water that is supposed to meet minimum standards. In other creeks, no replacement is planned. Mine shafts would change the way water flows from Buckhorn Mountain, affecting people dependent on that water. It would take 15-40 years to refill the aquifer inside Buckhorn Mountain. During that time, the creeks, springs, and seeps critical for healthy fish and wildlife would be deprived of water.

Water Rights for the Buckhorn Mine proposal approved by Ecology:
  • G4-34904 (Mine Dewatering). This application approved November 21, 2007 for mining, industrial and flow augmentation for a maximum instantaneous beneficial use of 100 gpm with a total proposed annual withdrawal of 12.6 acre-feet per year, derived from groundwater associated with mine dewatering and operations. This water would be collected from sumps within the mine and from dewatering wells.
  • G4-34905 (Domestic). This application approved October 25, 2007 for dust control, mining, and domestic use for site employees from a single well for a groundwater withdrawal  with a proposed of 5 gpm and 5.2 acre-ft/yr.
  • S4-34999 (Storm Water). This application approved October 24, 2007 for a surface water diversion for industrial and mining use to augment mine operational needs not met by the quantities requested under Application No. G4-34905, for 50 gallons per minute (gpm) (0.111 cfs). This water would come from collection of storm water drainage from ore and development rock stockpiles.
  • R4-35093 (Reservoir). This application approved October 24, 2007 permits a storage facility (surge pond) for water derived from mine dewatering and storm water.
  • CG-CCV1-4P200 (Newman). This change application, approved on September 26, 2006, changes the purpose, place, and time of use of a certificated seasonal irrigation water right for two groundwater wells to use in year-round dust control and seasonal mitigation of mining impacts on stream flows. The total certificated quantities for this right are 300 gpm and 200 acre-ft/yr.
  • G4-35084 (Lost Creek Ranch). This application approved November 21, 2007 for instream flow mitigation for a maximum of 125 gpm from one well in the Myers Creek watershed.
  • CS4-ADJ47P45 (Leslie Trust). This change application approved October 19, 2007 changes an existing water right from agricultural use to instream flow mitigation use during mining and during recovery of water levels associated with cessation of mine dewatering. for up to 0.156 cfs and 29.9 acre-ft/yr. Use would revert back to agricultural at the end of mitigation.
  • CS4-ADJ47P36 (Thorp Trust). This change application approved October 19, 2007 is a permanent change in use from stock watering to instream flow mitigation for 3 gpm.
  • CG3-29653P (K2 Mining). This change application, approved on September 28, 2006, changes the place of use from the K2 Mine to the proposed backfill borrow site in Ferry County. The total permitted quantities for this Water Right Permit are 50 gpm and 80 acre-ft/yr.
Problems with the water rights Ecology issued:
  • There is an unreasonable level of uncertainty regarding the hydrogeologic modeling of the impacts of mine dewatering and the resulting streamflow depletion.
  • Baseflow calculations of streamflows are questionable.
  • Aquifer properties where stream flow reductions would take place are scarce. The modeling inputs are based on untested assumptions of aquifer behavior.
  • Ecology fails to consider the cumulative impacts of granting Kinross water rights on local water supply and downstream water resources.
  • Granting water rights to Kinross would be inconsistent with past actions by Ecology.
  • The mitigation offered by Kinross does not come close to offsetting the harm to senior water right users and the public interest.
  • The speculative nature of the mitigation proposed does not meet the requirements that new water rights not impair existing rights and that new rights not be detrimental to the public welfare.
  • The mitigation offered by Kinross is off-site and out-of-kind, primarily enhancement of downstream wetlands and streams instead of a long-term commitment to on-site restoration.
  • No reliable mitigation is being offered for stream depletion during the post-mining refilling of the Buckhorn aquifer.
  • There is too much uncertainty that the mitigation plan would adequately protect existing rights and instream flows from harm.

2008 Settlement Details

Below are details of the agreement from the April 2008 negotiations between OHA and Crown/Kinross, whereby an underground mine would proceed on Buckhorn Mountain with additional monitoring and stream augmentation.

Key Monitoring Provisions:

  • Crown/Kinross will hire an independent third party to do their monitoring and reporting.
  • Crown will provide funds for OHA to hire its own independent monitoring company to do annual audits, quarterly visits, and random sampling and testing to analyze Crown’s third-party work.
  • Crown will increase water quality monitoring on the west slope of Buckhorn Mountain.
  • Crown will increase monitoring for sediment during spring runoff.
  • Crown will lower the threshold for corrective action if sedimentation increases in Marias Creek.
  • Crown will collect baseline water quality and quantity data for residents’ wells that are reasonably close to the mine if residents have concerns. 
  • Crown will send OHA all monitoring data.
  • OHA will be permitted access to the mine site.
  • Crown and OHA will attend an annual meeting to discuss monitoring results.

Key Mitigation Provisions:

  • As long as they are operating the dewatering wells, Crown will run water over to the headwaters of Gold and Bolster creeks to maintain seasonal baseflow.
  • After closure of the mine Crown, will retire 25 acres of the Lost Creek Ranch irrigation water (15 acres more than the agencies required). This would add water to Myers Creek and Bolster alluvial fan groundwater to replace the predicted permanent reduction caused by mining.
  • Crown agreed to permanent conservation easements of their mitigation sites including the reclaimed mine site and opening them for public access.  
  • Crown will also fund a significant amount of additional mitigation sites throughout the area. 
  • Crown will fix problems with residents’ wells that are caused by mining activity.
  • Crown will make a good faith effort to minimize truck hauling on weekends.

3D Visualization, Pacific Groundwater Group

Pacific Groundwater Group created a 3D visualization video for OHA as part of and in support of OHA’s comments on the draft NPDES Permit renewal in 2013. It begins with a visualization of the Buckhorn Mine underground workings with relevant faults and monitoring wells. It transitions to show: first the 2006 FSEIS capture zone, then the expansion of the capture zone proposed in the Draft NPDES, and then OHA’s proposed capture zone as seen from the south looking north. OHA’s proposed capture zone consists of the Draft NPDES depiction in the north, south and west and with the 2006 FSEIS depicted on the east side. The visualization then transitions to a view looking southwest from northeast of Buckhorn Mountain, and repeats display of the same sequence of capture zones.

About the Project:

Visualizing how groundwater in Buckhorn Mountain interacts with the mine, geologic faults, and dewatering wells is coming closer to reality with OHA’s 3D Visualization Project, which will increase everyone’s understanding of how water moves underground. At this point, we have created a number of animations circling a transparent depiction of Buckhorn Mountain. The color-coded animations include various dewatering and monitoring wells and piezometers in cross sections of interest, with see-through portrayal of the company’s projected faults and underground mine workings. The groundwater levels at key seasons will be added to assist in an analysis of how the dewatering wells are influencing groundwater flow.

Over the years of the mine, OHA has made numerous recommendations to the company that they analyze the actual groundwater monitoring data instead of relying on predictive models, which have not been effective at predicting actual conditions. Early in 2013, OHA initiated a 3D mapping project, which developed into the 3D visualization. OHA is hopeful that this will give everyone another tool to analyze the monitoring data and hopefully see where the gaps are in understanding groundwater flow paths. The end goal is to stop contaminants from escaping the mine.

Analysis by Stratus Consulting, Nov. 2010

Analysis of Water Quality Impacts at the Buckhorn Mountain Mine and Recommendations for Improvement

This report (PDF, 1 MB) responds to contaminant increases that triggered adaptive management in Gold Bowl Creek. The increases are more extensive than previously reported. The report provides an overview of important events at the mine, violations and orders submitted by Ecology, information on water quality standards and exceedences that have occurred but were not noted by Kinross or Ecology, and adverse environmental effects that have occurred and their current status. The report proposes recommendations for actions that could be taken by Kinross to increase environmental protection.

The use of reverse osmosis improved the water treatment facility and lowered some contaminants downstream from the discharge points, but others related to blasting have been decreasing more slowly.

Matrix of Annual Reporting Requirements

Click here to view the full PDF (67 KB)

After the first year of mine operation, not only were there were some significant water quality challenges on Buckhorn, but the required annual reporting was incomplete, lacking basic foundational data needed to analyze the mine’s impacts and the accuracy of model predictions. To quantify the inadequacy of the reporting, OHA completed an extensive review of the mine plans and developed a comprehensive matrix of annual reporting requirements. Using this matrix, OHA assessed the degree to which the company satisfied the requirements for Water Year 2008 and presented the results to the Department of Ecology and Kinross.

Issues by Water Year: 2008

2008 Annual Monitoring Report Summary

While underground mining reduces the impacts when compared to the previously proposed open pit, significant water quality and quantity issues remain.

In April 2009, the first annual meeting took place to review the Water Year 2008 monitoring reports. The purpose of the meeting was to provide input towards the discussion of the adequacy of the monitoring plans, to monitor the hydrologic aspects of the Buckhorn Mine and mitigation, and to suggest modifications that might be needed for adaptive management. The annual reporting requirements are extensive.

After brief introductions including representatives from Washington State Department of Ecology, and Washington State Fish & Wildlife, the USDA Forest Service, Crown/Kinross, Golder Associates and OHA, OHA started the meeting off with an overview of our issues and concerns and a presentation by our consultant Ann Maest of Stratus Consulting.

OHA expressed grave concern over the failure of Crown/Kinross to submit reports required by the Hydrologic Monitoring Plan that are needed to understand the impacts of the mine. Crown/Kinross consultant, Golder submitted nine technical memos to the agencies that related to the Adaptive Management Plan. The memos were not integrated and were poorly organized. There was no table of contents or index and it was difficult to discern if requirements were met. We expressed our concern and frustration that there was not enough time to accomplish the objectives of the annual coordination meeting in the four hours allotted to it. Many of the agencies in attendance also expressed concern regarding the completeness and organization of the memos that were presented. Because of the incompleteness and poor organization of last year’s reporting and lack of time, we never actually got to the point during the annual meeting of discussing the adequacy of the plans or if modifications may be needed.

Since that time OHA has done an extensive review of the plans to develop a comprehensive matrix of annual reporting requirements and their degree of completion for 2008. After reviewing the memos and reports, in cooperation with Kinross, OHA finds the 2008 annual reporting incomplete and lacking basic foundational data needed to analyze the mine’s impacts or the accuracy of model predictions. OHA’s analysis shows that the reporting does not meet the requirements of the plans.

Some Highlights from OHA’s Independent Review

OHA presented a series of graphs and maps showing location of increasing levels from baseline of nitrate, sulfate, ammonia, and chloride.

Annual Reporting Requirements:

  • Hydrologic Monitoring Plan (HMP) – No annual reports received
  • Adaptive Management Plan (AMP) – Memos not integrated (hard to discern if requirements are met), memos are not reports
  • Ecological and Aquatic Resources Management Plan – Annual reporting incomplete

Baseline (Conditions that existed before construction and mining):

  • Baseline water quality values are different for Kinross and Ecology
  • Some baseline values are higher than current concentrations
  • Baseline should be reevaluated so changes from baseline water quality conditions are apparent

Analytical Issues:

  • Detection limits
    • Some numeric values not in database
    • Some metals detection limits are too high compared to baseline/standard
    • Required detection limits are not noted in permit
  • Dissolved vs. total measurements

Missing Analysis:

  • On-site precipitation data
  • Continuous flow inflow/effluent data
  • Surface water monitoring points
  • SW-15: flow and water quality
  • According to HMP, flow should be measured, but no frequency was set. Data are available from Kinross but not in monthly monitoring database.
  • Groundwater – Depth to water at Infiltration Gallery should be reported as depth below ground surface (permit condition) rather than below casing.

Mine Inflow Water Quality: Measured vs. Predicted

Southwest Zone: higher than predicted sulfate, aluminum, arsenic, fluoride, lead, manganese, nitrate, and zinc–Makes treatment more difficult than expected

Flow Evaluations:

  • Myers Creek Augmentation Study
    • The objective of the work was to see if augmentation of the stream with Lost Creek well water would increase flow at the international border (SW-15)
    • Flow at SW-15 was not monitored during the test
    • The augmentation study occurred just after a major storm, making results difficult to interpret
    • Study should be repeated under better weather conditions, and flow should be measured at SW-15
  • Adaptive management
    • Measured vs. predicted flows
    • Locations recommended for additional flow

OHA’s Review Identifies Shortcomings

OHA’s analysis after almost one year of operations was hindered by incomplete annual monitoring and reporting of data. The monthly monitoring of surface and ground water around the mine shows that specific constituents continue to rise above baseline although they remain below standards. We consider the lack of annual monitoring reports specific to each requirement of the Hydrologic Monitoring Plan a potential permit violation. OHA acknowledges that some of the required information may be included in the Adaptive Management Plan memos but, we do not believe this meets the permit requirements. Kinross has expressed a commitment to get it right.

Possible Violations:

  • No on-site meteorological data as required
  • No reporting of flow data for SW-15 (Myers Creek at international border)
  • Outfall 002 is discharging from pipe to rubble, not to stormwater pond as required
  • Inflow/effluent – continuous flow data required but not reported

Measured vs. Predicted Flow Issues:

  • Measured low flows (fall/winter) are often substantially lower than modeled baseflows
  • FEFLOW model does not adequately simulate pre-mining conditions
  • Need precipitation data from the mine and historic stream flows as input to model

Other Issues:

  • Failure to complete conservation easements for mitigation properties
  • Failure to submit annual reports in a timely fashion
  • Failure to make a good faith effort to administer monitoring plan
  • Many surface water points monitored only from June-Sept
  • Some required data in AMP reports; no HMP reports
  • Water use data statistics and photos missing
  • Stream flow data missing
  • Evaluation of predictions in groundwater flow model not adequate
  • Reporting of additional monitoring (NPDES S3.D)
  • Water level or flow are required by the HMP and implementation of HMP is required as a conditions of the NPDES – then flow should be required as part of the NPDES permit

Recommendations

  • Fix weather station at Buckhorn Mountain
  • Re-evaluate modeled baseflow with data from Buckhorn Mountain weather station and historic data
  • Monitor and report flow at SW-4, SW-12, SW-13, SW-15
  • Re-do Myers Creek augmentation evaluation with monitoring point at SW-15
  • Re-evaluate baseline water quality for surface water and groundwater
  • Analytical issues
  • Detection limits
  • Dissolved and total metals for surface water
  • Continue to improve treatment to better remove sulfate, nitrate/ammonia, chloride; consider using less explosive
  • DMRs and composite database should include flow monitoring and OHA settlement monitoring
  • “Frozen” monitoring points should be photo-documented
  • Provide water use data
  • Need integrated annual reporting
  • Mine site (groundwater, surface water, influent/effluent, dewatering wells)
  • “Mitigations” (compensation projects)
  • The next annual meeting should be a full day long and reporting submitted when due

Locations for Additional Flow: Adaptive Management

  • Monitor and report flow at SW-4 (Lower Gold Creek), SW-12 (Lower North Bolster Creek), or SW-13 (Lower South Bolster Creek) – not currently required
  • Flow monitoring is required at upstream locations on Gold Creek (SW-10), North Bolster Creek (SW-11), and South Bolster Creek (SW-14)
  • Depletions are predicted for SW-4, SW-12, and SW-13
  • Monitoring at downstream locations provides better picture of dewatering effects
  • Monitor and report flow at SW-15 (Myers Creek at international border)

Overall OHA expressed concern that predictions of operational and post-closure water quality were too optimistic, due in large part to underestimation of contaminant concentrations from geochemical testing results. The amount of rock predicted to become acidic over short and longer time frames were also underestimated, and plans for management and identification of acid-generating rock poorly defined. (See page 5 of Buckhorn Bulletin, March 2008)

  • The geochemical tests used to define potentially acid-generating (PAG) rock will underestimate the acid-generation potential of rocks in the development rock stockpile and in the underground mine.
  • The short test length and high detection limits for metals renders most of the humidity cell test results almost useless as indicators of water quality.
  • The prediction that development rock will not become acidic in the time that it is exposed during mining is not supported by the mineralogic information or the HCT data.
  • Predictions of operational and post-closure water quality underestimate the ability of the mined materials to generate acid and leach contaminants because they rely upon a series of assumptions and analytical and modeling approaches that underestimate the reactivity of mined materials.
  • Predictions of mitigated post-closure mine water quality does not consider the presence of reactive mine wall rock and underestimate the exceedences of groundwater standards in the underground mine
  • The use of “passivation” techniques is experimental, requires a high degree of engineering success, and is highly unlikely to prevent groundwater exceedences in the underground mine under post-closure conditions.
  • The quantitation limit (QL) for effluent parameters is not defined in the NPDES permit. If the QL is not at least three to five times lower than the effluent limit, it will not be possible to distinguish a non-detect value from an exceedence.
  • No specific quality assurance/quality control (QA/QC) criteria are required for sample reporting.
  • No maximum daily limits are set for surface water discharges for a number of important parameters.
  • The effluent limits for several of the contaminants are set higher than drinking water standards.
  • The effluent limits for cadmium and nickel are much higher than the federal Clean Water Act limits using the relevant aquatic life hardness-based criterion values at the hardness value suggested in the permit.
  • Chronic and acute tests should be run when concentrations in the stream are the highest.
  • The discharge of treated effluent to groundwater will cause exceedences of toxics in surface water.
  • In addition to water quantity or flow monitoring, Myers Creek and tributaries should be monitored for water quality changes that may result from discharge of mine pool water under post-closure conditions.

Some general and specific examples of issues related to the 2008 annual reporting requirements are as follows:

  • The annual monitoring reports were poorly organized and difficult to follow. To review any aspect of the Buckhorn Mine annual reports required navigation and cross referencing through multiple plans, reports and memos.
  • NO required Hydrologic Monitor Plan (HMP) report(s) were submitted to the agencies. The plan is very specific as to the method, location, frequency, and reporting period for each aspect of the plan being monitored. While the Adaptive Management Plan (AMP) uses monitoring information to compare and evaluate, the specific requirements of the HMP have a much broader scope, and many of the required elements had not been reported. If Kinross thought that the HMP reporting requirements were contained in the AMP, some attempt should be made to document which specific requirement was being addressed. OHA did extensive cross-referencing and found many missing HMP elements. (See Stratus Consulting, 2009, Annual Reporting Requirements)
  • Much of the required analyses and data were missing. The AMP reporting contains quite a bit of very useful information that has been greatly improved since the annual coordination meeting with the addition of a table of contents for the ten memos that Golder provided when OHA asked for it. However, much of the data analysis and interpretation required annually has not been reported.

For example:

  1. The discharge to the NPDES outfalls was not reported.
  2. The AMP requires comparison of operational data with pre-mining predictions and conditions, but many of the comparisons were not conducted or only partially conducted.
  3. The on-site meteorological station did not function for most of 2008. The failure of Kinross to maintain a functioning weather station on Buckhorn Mountain makes problematic the evaluation of whether water resource impacts are mine or weather related. Kinross made an effort to provide alternative data, but given the very localized weather patterns for the area, meteorological information must be site-specific (i.e. on Buckhorn Mountain) to be representative.

It is not enough to simply say, “We will do better next time.” Ground and surface water predictions need to be reevaluated and improvements need to be made as part of adaptive management for the mine.

Issues by Water Year: 2009

Out of Adversity Comes Opportunity

The 2009 annual coordination meeting to discuss the Buckhorn Mines took place at the Eagle Cliff Grange on the bank of the Kettle River on March 17th. Final monitoring reports were distributed to the agencies and OHA on March 3rd. OHA’s consultant, Ann Maest of Stratus Consulting, presented our review of the documents along with an independent review of the monitoring data. OHA offered recommendations regarding water treatment, streamflow comparison, capture zone, development rock, the Kettle River Facility, discharge monitoring reports and composite database as well as the timing of the next annual reports.

The purpose of the annual coordination meeting is to review the hydrogeologic and water quality monitoring of the mine and suggest modifications to plans that will help ensure protection of the environment.

WY 2009 Violations: Arsenic (December, January, April); Total Dissolved Solids (TDS) (May); ammonia (June); zinc (July); chlorine (July)

Cleaner Reports, Cleaner Water… but concerns remain regarding certain missing and faulty data and analysis

This year’s evaluation is based on Water Year (WY) 2009, which began on September 31, 2008 and ended on October, 1, 2009. WY 2009 reports were much improved over last year’s reports. The reports were well organized and for the most part addressed the issues directly, spelling out the requirements early.

Shortly after last year’s annual meeting, numerous violations, orders and a $40,000 fine were issued to Kinross/Crown for various water quality violations and failure to maintain the mine’s capture zone. The violations and orders continued until August when improvements to the Water Treatment Facility were implemented. Since that time no violations have been issued.

Summary Findings
  • Water Treatment Plant improvements and approach were positive – more improvements needed
  • A number of sites are adversely affected by underground mine and/or treated water releases; WY 2010 will show if improved; none of the levels are alarming
  • No large decreases in streamflows, but methods for estimating changes and meteorologic data need improvement
  • Groundwater capture has not been demonstrated – seasonal variability in groundwater levels overwhelms drawdown signal at many of the wells

More information can be found on pages 4-5 of the April 2010 Buckhorn Bulletin Newsletter, with updates, issues, and recommendations regarding:

  • Water Treatment Plant (WTP)
  • Water Quality Issues
  • Development Rock
  • Evaluation of Mine Dewatering Impacts to Streamflow
  • Capture Zone
  • Kettle River Tailings Facility

Draft Modification NPDES Permit

2009 also brought a draft modification NPDES, which involved some serious water quality issues:

On May 14, 2009, Washington State Department of Ecology issued a draft modification NPDES (National Discharge Elimination System) permit and fact sheet.

The purpose of the modification was:

  • To add monitoring for chlorine to the NPDES. Chlorine would be used to reduce unexpectedly high levels ammonia.
  • To add some aspects of OHA’s settlement agreement to the permit such as increasing surface water monitoring during April, May, and June for turbidity and Total Dissolved Solids from monthly to bi-weekly for monitoring sites SW-7, 8, & 9 downstream on the east side of the mine and at three sites on Marias Creek Rd.
  • To add grease and oil monitoring for water in and out of the treatment facility, the lack of which was an oversight from the original permit.
  • To add another round of chronic and acute testing since the first one was not conclusive.
Issues:

There was no disclosure of the impacts of increased chlorine on aquatic organisms. The public has a right to know the impacts of decisions before they are made. OHA asked that Ecology show that adding chlorine to the environment would be less harmful than other methods of reducing ammonia levels such as biological treatment, artificial wetlands or adding additional zeolites to the treatment facility. OHA also asked that an AKART (All Known and Reasonable Technology) be done.

The engineering report for this NPDES modification was approved in February 2009 and included a modification of the point of discharge of Outfall 002 from the storm water infiltration pond to from a pipe at the top of riprap on the hillside above Gold Bowl Creek. Ecology had wrongly considered this change in discharge point a minor modification since the change has previously caused erosion and slope instability, in violation of permit limits and so not covered under 40CFR122.63. There was no documented justification or cause for not using the stormwater pond to infiltrate discharge of Outfall 002.

The effluent failed the acute toxicity testing if any aquatic test organism has less than 80% survival in 100% effluent. The toxicity tests conducted in September 2008 showed no survival (100% dead) in 100% effluent. Based on these results, additional monitoring should have taken place but did not.

The modification failed to include other provisions of OHA’s settlement monitoring that are west of the mine. According to the settlement agreement water quality monitoring similar to NPDES requirements will be conducted on SW-5, 10, & 11 also. OHA asked that these monitoring points also be included in the modified permit.

Detection limits for a number of toxic metals were too close to, or in some case even higher than, relevant standards. OHA asked that these detection limits be lowered and included in the permit and monitoring reports.

Issues by Water Year: 2010

After more than three years of operation, ongoing issues continue to ebb and flow, such as some significant water quality challenges on Buckhorn that have corrective action in process.

Water Year 2010 Annual Meeting

The annual coordination meeting to discuss Buckhorn Mine’s Water Year 2010 data took place at the Eagle Cliff Grange on the bank of the Kettle River on March 15th. Annual monitoring reports were submitted to the agencies a few weeks prior to the meeting. The purpose of the annual meeting is to review a summary of the previous year’s monitoring data, discuss the adequacy of monitoring plans and recommend any modifications that might be needed. OHA opened the meeting with a presentation of our analysis of the monitoring data, and followed up with a presentation and the independent review by Ann Maest of Stratus Consulting, which laid out our concerns regarding the company’s analysis. OHA also raised concern over contaminated mine leakage and offered suggestions to address the issue.

OHA submitted a memorandum outlining changes to the Adaptive Management Plan we recommend and a list of actions that would improve the environmental reporting and performance of the mine. A separate memo was also submitted regarding Kinross/Crown’s failure to apply the required shotcrete to potentially acid generating (PAG) mine walls.

Kinross began their presentation with an overview of how much they contribute to the community with jobs and donations and how much gold has been produced. Next, they provided an overview of the capture zone issue, the water treatment facility and surface and ground water quality. Prior to the annual reporting, Kinross adamantly maintained that the capture zone was effectively intercepting all mine contaminants. At the annual meeting, Kinross consultant, Golder Associates, presented quite another story. After rerunning the groundwater model, it is clear that four monitoring wells in the North Lookout Fault-3, east of the mine, are outside the capture zone and that it could take years for the contamination to dissipate. Mine contamination has also leaked west of Buckhorn into the surface water of South Bolster Creek.

OHA Recommended That…

Operational Changes should be Documented:

Adaptive management will continue to play a critical role in mining operations. In fact, some of the most important operational changes that have taken place over the past year are not included, or are minimally mentioned, in the annual reporting. For instance, the renovation and upgrade of the treatment facility has greatly improved effluent discharge, thereby reducing downstream impacts; however, it is not discussed in any detail in the annual reports.

Unless the changes that have taken place are documented, future mine staff and regulators will only have a tangential understanding of how and why things are done the way they are done. This is an inadequacy of the Adaptive Management Plan (AMP). OHA recommended that a provision be added for annual reporting to include an explanation of the issues the mine has addressed over the year as well as the proposed or implemented solutions. Kinross and the agencies agreed with OHA that annual reporting will now include major changes that have been implemented at the mine, including an explanation of reasons for instituting the changes.

Faults Should be Mapped:

The network of fractures throughout the mine and underlying the facilities are more extensive than previously understood by mine officials. Contamination from the underground mine, and likely the waste rock/ore stockpile, travels underground through interconnected faults, bypassing the dewatering wells and ending up in ground and surface water down-gradient from the mine. The increase in sulfates could indicate the start of acid mine drainage. Nitrates from blasting have increased to the west, south, and east of the mine.

While the 2010 shotcrete inspection report failed to present the required volume and method of shotcrete application, it did reveal that additional faults exist, which have not been noted in any previous documentation. Understanding the location of new faults is well established as a critical factor in understanding the movement of contaminants.

The Development Rock Management Plan (DRMP) provides procedures for identifying PAG rock to secure safe storage and disposal. Part of that process includes mapping the location from which PAG is mined. OHA suggested that the quarterly reporting of development rock characterization should be modified to include quarterly mapping of PAG locations and mapping of any fault and fractures that are identified while mining. These reports would be summarized annually. This modification was accepted.

OHA also recommended that additional investigations of hydrologic pathways and faults on the mine site should be conducted. Studies could include additional pump tests, with response wells located across known or suspected faults; additional geophysical studies; and additional geochemical studies of water quality in mine sources and at stream and groundwater monitoring points. These suggestions are being considered.

Shotcrete is Needed To Prevent Acid Mine Drainage:

One very important aspect of the DRMP and AMP that is known to be highly effective has unfortunately not been implemented. Shotcrete inspection reporting reveals that only limited amounts of shotcrete were applied for PAG pacification last year and none in the previous year. Shotcrete is supposed to be applied to all PAG headings. For the last three years there have been increasing amounts of PAG rock and a corresponding greater amount of PAG headings. The application of shotcrete is not discretionary; it is a provision of the DRMP and AMP to be implemented because it would reduce the likelihood of Acid Mine Drainage (AMD).

The AMP for Development Rock states, “Shotcrete will be used to prevent air and moisture penetrating into blast fractures in the Damaged Rock Zone (DRZ), thus reducing oxidation and interaction between DRZ PAG rock and mine water. This shotcrete will also reduce oxidation (by limiting airflow) of DRZ PAG rock that remains exposed above the water table after the groundwater system has re-equilibrated. As part of the adaptive management plan, the extent of the shotcrete will be determined based on the mine engineer’s mapping of PAG rock, and water flows into the mine.”

Shotcrete creates a reasonably effective barrier to prevent AMD, whereas backfilled cement does not create an effective barrier. Backfilled cement performs a structural function so that additional mining can take place, but does not necessarily form a seal. As a result, water that infiltrates around and through the backfilled cement rock has a high probability of eventually picking up contaminants and spreading the contaminants into the ground and surface water. Unfortunately, for the past two years, little or no shotcrete has been applied. Kinross says that from now on they will apply shotcrete but they still think that no shotcrete is needed if cemented backfill fills the mine-shafts. This is not acceptable.

At the annual coordination meeting, OHA requested that Ecology require Kinross to go back and shotcrete all mine-shafts that contain PAG rock. Some of the shafts have already been filled with cement. OHA has asked that this cement be removed and shotcrete applied as required. The agencies will consider this request. OHA also requested that in the future, no cemented rock fill is placed until the PAG headings are properly sealed (shotcreted). OHA requested that PAG stockpile discharge monitoring occur monthly, a suggestion that will be implemented, as well as more often during spring runoff, which the company is considering.

Adaptive Management Issues

Kettle River Tailings Facility: There is a trend of increasing concentrations of nitrate, sulfate, and TDS in surface water; this should require Adaptive Management Plan action.

  • 1
  • 2
Go Back