Attachment_2_-_Sample_Monitoring_Plan.pdf

Elk Tunnel Passive Treatment Performance Evaluation and Monitoring Plan - Draft Plan

The attached BLM document is the PEMP for the subject CERCLA Site

ELK TUNNEL PASSIVE TREATMENT PROJECT

EPA ID# CO0001411347

Performance Evaluation and Monitoring Plan

REGULATORY REQUIREMENTS FOR PERFORMANCE EVALUATION AND

MONITORING PLANS

The BLM is responsible for the implementation of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) on BLM administered lands. Executive Order 12580 and

13016 delegated to the Department of the Interior the CERCLA authority ; the responsibility for responding to releases of or potential releases of hazardous substances, such as those documented to be occurring at the Elk Tunnel Site (Site) in 2002 (BLM, Removal Action Memo 2003). Secretarial

Order 3201 further delegated many of the CERCLA responsibilities and authorities to the BLM State

Directors through Washington Office memorandum (2000-093).

The National Contingency Plan (NCP) (40 CFR 300.435) and CERCLA (40 CFR 121) require performance monitoring and evaluation of remedial actions to ensure that a CERCLA remedy is, and continues to be, protective of human health and the environment. Based upon this requirement, the

EPA developed guidance regarding “5-year Reviews”. The EPA notes that such reviews are specific to remedial actions; however, leeway is allowed for (Policy) and applications towards removal actions are possible on a site-by-site basis. The BLM-Colorado AML program considers the overall objective of 5-year reviews as applicable to removal actions, but with some noted exceptions. The scope is contingent upon a site’s overall complexity, elements of the response action and the potential consequences of a failure.

Per BLM’s Handbook H-3720-1 (the AML Handbook), the BLM adopts as its policy this same requirement for evaluations of removal actions as well as remedial actions. This is specifically found in, the BLM Abandoned Mine Land Program Policy Handbook (3/20/2007), Table 4.

However, due to BLM budget constraints and program priorities not all of the EPA’s 5-year Review

Process is adopted by the BLM. The BLM’s performance evaluations focus on site visits for inspecting the integrity of engineered surface structures, the collection and review of any necessary monitoring data. Lastly, the BLM documents and files a performance determination to complete the performance evaluation process.

SITE BACKGROUND INFORMATION AND SUPPORTING CERCLA INFORMATION

The Elk Tunnel is located within the Cement Creek drainage, and consists of a flowing adit and a small waste rock pile (1,100 cubic yards). The Site is located entirely on BLM administered lands and encompasses approximately 1 acre. It is located within the Animas River Watershed in San Juan

County, Colorado, approximately 4 miles west of Silverton, Colorado. Its specifically located at an elevation of 10,200 feet MSL (mine tunnel), latitude 370 52’ 9” North, longitude -1070 40’ 27” West.

The updated location of the project using state of the art GPS equipment (2014) is given as

37.87020500 North, -107.6754790 East or UTM Zone 13 South, 4196769.91m North, 265635.45m

East. The Site can also be described as the SE¼SE¼SW¼, Section 30, Township 42 North, Range 7

West, NMPM.

This Performance Evaluation and Monitoring Plan (PEMP) is specific to the Elk Tunnel and and the components of its passive treatment channel, e.g., channel and ponds. BLM pursued this CERCLA action since the Acid Mine Drainage (AMD) is detrimental to public lands at the site as well as downstream of the site administered by the federal government. BLM has direct jurisdiction over this site.

The Elk Tunnel is a flowing mine adit and a source of Acid Mine Drainage (AMD) to Cement Creek, which flows into the Animas River near Silverton. Flows from the adit range from 0.30 to 0.58 cubic feet per second (cfs) averaging 0.404 cfs or 181 (range 135-260) gallons per minute (gpm). Peak flows of up to 260 gpm have been measured emanating from the adit. Summary results from the

EE/CA show that flow rates from the adit have remained generally uniform over time.

The adit water pH has remained nearly neutral at an average of 6.94 (ranging from 6.14 to 8.13).

The analyte concentrations in the Elk Tunnel are generally similar to or less than analyte concentrations in Cement Creek upstream of the site. 1998 water samples indicate that the Elk

Tunnel contributes an average heavy metal content to Cement Creek as follows (based on total samples): aluminum 0.25 lbs/day, iron 11.28 lbs per day, manganese 4.55 lbs/day, zinc, 0.45 lbs/day. Using these values, it is calculated that the adit flow contributes 5 percent of the total loadings from all draining mines into Cement Creek. It can also be noted that the concentrations of certain metals are above the aquatic standards for Cement Creek.

This CERCLA non-time critical removal action was initially administratively begun by BLM in 2002, with assessment studies dating back to 1997. An Engineering Evaluation/Cost Analysis (EE/CA) was initially completed April 2002 through the BLM National Science and Technology Center. After which the Removal Action Memo (RAM) was prepared August 29, 2003. The Site’s complete administrative record has been located. The LR2000 COC registry number is 077146.

In the early 1990’s, the Colorado Water Quality Division began to evaluate water quality in the

Upper Animas River watershed. Their studies found significant metal contamination from historic mining. In 1994, the Animas River Stakeholders Group (ARSG) was formed with the intent of studying and addressing the contamination of the Animas River watershed and also forming a collaborative group for a community based partnership. A “Use Attainability Analysis (UAA)” was prepared after a watershed characterization was initially completed. This UAA identified and ranked the AML sites which were contributors to the degradation of the Animas River water quality. The Elk Tunnel site was identified as a high priority (#26) for cleanup as based on metal loading and contamination.

This action was taken by BLM under their CERCLA authority, and per the CERCLA assessment it was determined that this removal action would reduce significant threats to public health, welfare, and the environment by the uncontained presence of hazardous substances at the Site.

The hazards and risks identified in the RAM include: (1) Reduce or eliminate the dissolution or release of metals; (2) Reduce or eliminate the generation of acidity from the mine drainage.

A summary of the assessment data regarding the observed releases and potential releases provides the following information:

Metal concentrations (totals) for a 1997 sample obtained at the adit are: iron 4500 ug/l, manganese 1900 ug/l, and zinc 240ug/l. The water pH at the time of sampling was 7.6.

These values are indicative of other samples taken prior to treatment actions. These specific metal concentrations exceed Colorado basic stream standards for metals, class I aquatic life standards, and exceed reportable quantities under CERCLA. Although the concentrations of toxic metals are not exceptionally high, the large adit discharge results in a large metal load to Cement Creek. It appears there is a significant risk to aquatic life as indicated by in-situ studies, toxicity studies and by the threshold comparison evaluation.

The analytical results (1999) for heavy metals on the mine dump associated with the Elk

Tunnel show moderate amounts of copper, cadmium, iron and lead and zinc contributions to the hydrologic system. It was concluded through other studies that these contaminants were not a significant source to the water quality.

Elk Tunnel location map

REMOVAL ACTION OBJECTIVES AND RESPONSE TAKEN

The goals of the removal action as defined in the Removal Action Memo (RAM) were to:

Reduce or eliminate the dissolution or release of metals.

Reduce or eliminate the generation of acidity from the mine drainage.

Reduce or eliminate metals loading to Cement Creek.

Confine the action to the existing footprint.

Minimize operating and maintenance cost .

Reasonable capital cost.

Satisfy state and federal Applicable or Relevant and Appropriate Requirements (ARARS).

Based upon the Removal Action Objectives (RAOs), the following aspects of the response action were integrated into the final design:

An adit drain and lined collection channel was constructed to collect adit water and channel it to the passive treatment channel and associated treatment and settling ponds. The passive treatment and settling pond locations were designed to fit into previously disturbed areas, generally along the shoulder of a pre-existing mining road.

It was anticipated that maintenance costs would be minimal with this type of treatment and initial construction costs would be low.

The passive treatment was designed to include a geomembrane liner to prevent loss of treated water, gabion baskets for anchoring and stabilization of the limestone media and the channel designed to flow into an existing wetland before entering Cement Creek.

The AMD was diverted off the existing waste rock piles.

This removal action is anticipated to help Cement Creek to meet water quality standards, but would not singularly accomplish this goal. There are no numeric surface water or groundwater standards that this action is intended to achieve by itself. However, reclamation goals have been established and are expected to assist in achieving the following overall Cement Creek water quality expectations for the following:

Constituent Total (ug/l) Aluminum 87 Iron 300 Manganese 1,000 Zinc 194

Elk Tunnel Response Action - 2003

Due to the identified releases to Cement Creek and ultimately the Animas River, a response action was begun in 2003 to mitigate risks from the AMD.

A limestone lined treatment channel and associated in-line settling ponds were installed downstream of the adit within previously disturbed areas. The adit flow would also be diverted off the existing waste pile through this action to assist in neutralizing AMD from the Elk Tunnel and detain the precipitant prior to entry into the existing Cement Creek drainage. Due to the significant amount of sludge precipitant that collects in the constructed ponds, maintenance is expected to be required every ten years or sooner(based on current maintenance timeframes) in the form of manually excavating the precipitants and removing them from the site.

The treatment channel was also underlain with geomembrane fabric to stop infiltration of contaminated water into any groundwater system.

Runon and runoff controls were used at the site to prevent surface water from entering the treatment channels or ponds.

SUMMARY OF RESPONSE ACTION AND PASSIVE TREATMENT CONSTRUCTION

Since 1994, extensive characterization investigations have been carried out by various entities

(BLM, USGS, Animas River Stakeholder Group, CDRMS) in Cement Creek and the Animas River watershed. These site characterization studies indicate that drainage from the Elk Tunnel and associated runon to one waste pile was a significant contributor of metals loading to the Animas

River watershed. Through these investigations, it was estimated that the Elk Tunnel contributes approximately 5% of the total zinc load to Cement Creek, at concentrations that exceed aquatic life standards.

Through the BLM EE/CA process, it was determined that the best approach to reduce metals loading from the AMD into Cement Creek would be to construct a lined passive treatment channel with 3 settling ponds and to insure that the adit drainage did not flow onto the existing mine waste dump. Originally, the AMD from the adit ran over the existing waste rock dump, through wetlands created by the annual flow and into Cement Creek.

Construction began in 2003 and was completed that year.

There were no records of significant differences from design to actual field construction in any report; therefore it is assumed that it was constructed as designed.

The AMD from the tunnel has been collected in a geomembrane lined collector channel and ponds.

The adit effluent (AMD) is treated in limestone lined ponds and a limestone lined channel which eventually flow to natural wetlands at the bottom of the hillside adjacent to Cement Creek. . The run-off and run-on for surface water at the site was incorporated into the design to keep these waters from entering the treatment area. The treatment channel was designed to eliminate surface run-on issues.

Total cost for this project was estimated at approximately $145,876 with annual O&M costs estimated at approximately $3,000.

.As-built drawing of constructed treatment area - 2003

PREVIOUS MONITORING AND RESULTS

Construction of the treatment channels and ponds was completed in 2003 (as planned) and per the approved design. BLM, the Animas River Stakeholders Group (ARSG) and DRMS have cooperatively implemented post-completion qualitative monitoring of the site annually from 2003 for: erosion monitoring, unauthorized use, sludge management, pond vegetation growth assessment, water quality (limited data), and diversion and treatment channel construction and monitoring. Based upon this information, the treatment of the AMD has been determined to be successful. Future monitoring of this site will be required, but the overall design appears to be functioning as anticipated and currently performing as designed.

Minimal maintenance to the channels and ponds has been required to date and consists of channel and pond cleaning and minor gabion maintenance.

There has been additional biotic monitoring which includes sampling benthic macro-invertebrate and fish communities within the Animas River drainage, in order to denote any aquatic response to the continued remedial actions within the Animas. The most recent surveys on record were completed in 2010. The initial surveys were completed in the early 1990’s. The Colorado Division of

Wildlife also completed an additional fish study in 2013 to compare to their earlier studies. Water quality sampling continues on a yearly or near yearly basis. Cement Creek appears to not have any macro-invertebrate activity – due to poor water quality.

A gate and applicable signage was established to prevent the public from camping or driving on the site and has been successful to date.

PHOTO’s OF THE SITE

View of the cabin located adjacent to the upper pond.

View of the lower pond looking generally south. Outfall at far end of pond flows into a natural wetlands area and eventually to Cement Creek.

MAINTENANCE TO DATE

Maintenance in 2005 added 8 check dams in the channel, baffles in the ponds, and replaced limestone in the channel at a cost of $30,910.

Maintenance in 2012 was required to clean the ponds because sludge had built up in the settling ponds to the point the ponds were in danger of breaching. Sludge was removed by hand, since shoveling was needed to chop out the roots of colonizing vegetation. Pumping was only moderately useful. Sludge was placed in various locations at the site for drying. The dried sludge was moved by backhoe (additional dirt work was done along the bottom leg of the switchback to accommodate this) and consolidated in a storage pit on site (in the road cut slope south of the end of the limestone channel). This required approximately 12 person days of staff time, and about $13,000 of heavy equipment time.

Cleaning and removal of the material from the constructed settling ponds will be required every ten years, as based on previous experience and is and will continue to be a maintenance requirement. It may be worth experimenting with pumping the sludge more frequently to see if that will minimize total cleanout costs. Limestone media will also need to be replaced on an as needed basis.

Maintenance is required for the diversion channel, runon and runoff control and treatment channels and ponds for the site.

Crew cleaning the middle pond in 2012. Note that flow has been turned off. Note that green vegetation has grown in the sludge collected behind the baffles, requiring shoveling to remove.

PERFORMANCE EVALUATION to determine if the Removal Action Objectives were met Based upon monitoring observations and data, the BLM must evaluate the goals of the removal action, e.g., RAOs to ensure the action is performing correctly. Overall these goals are: (1) Reduce or eliminate the dissolution or release of metals; (2) Reduce or eliminate the generation of acidity from the mine drainage: (3) Reduce or eliminate metals loading to Cement Creek; (4) Confine the action to the existing footprint; (5) Minimize operating and maintenance cost; (6) Reasonable

Capital Cost; and (7) Satisfy state and federal Applicable or Relevant and Appropriate Requirements

(ARARS).

Based on the characteristics of the AMD and the completion of the removal action, the following

RAOs were evaluated and are considered to be achieved.

Reduce or eliminate the dissolution or release of metals.

Recent Sampling Data – 2003-2010 sampling summary (17 adit and 13 channel sampling events)

Total Aluminum

Discharge Adit Loading

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low .035 -.079 -232

High .071 .040 57

Overall

-38

Total Iron

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 10.9 6.3 58

High 18.8 8.0 42

Total Manganese

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 4.9 .558 11

High 7.6 1.6 21

Total Zinc

Discharge Loading (lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low .520 .148 28

High .882 .176 20

Average total metal loading and reduction rates (lbs/day) for low and high adit discharge rates.

Values in bold represent overall heavy metal percent reductions. Negative values indicate an increase in total loading between the adit and the outfall.

Dissolved Aluminum

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low .057 -.055 -99

High .249 -.002 -1

-89

Dissolved Iron

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 7.8 7.0 90

High 15.7 17.4 92

Dissolved Manganese

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 4.7 .591 13

High 7.5 1.8 24

Dissolved Zinc

Low .531 .271 51

High .933 .445 48

Average dissolved metal loading and reduction rates (lbs/day) for low and high adit discharge rates.

Values in bold represent overall heavy metal percent reductions. Negative values indicate an increase in

There is a 17-45% (total metals) and 20-93% (dissolved metals) reduction in Fe, Mn and Zn from the limestone-lined treatment channel and settling ponds. Iron (Fe) is best adsorbed, while Aluminum (Al) actually showed an increase in loading along the treatment channel.

Since Aluminum baseline concentrations are relatively low in this system, this is of minimal concern. Cadmium and copper loading and reduction rates were not analyzed because they had non-detectable concentrations according to laboratory analysis standards.

No distinct relationships between discharges rates and reduction potential were noted, indicating that contact time with substrate material may not be a limiting factor at this site.

Additionally, no clear trends were noted between time and load reduction, signifying that adit water chemistry is stable and/or the treatment system has not yet reached capacity.

There could be a relationship between algae coating and sludge on the limestone media and aeration of the AMD in the treatment channel which could affect the precipitation or reduction in the contaminants of concern.

This removal action is anticipated to contribute reductions in metal loadings in Cement

Creek to meet water quality standards, but would not singularly accomplish this goal. There are no numeric surface water or groundwater standards that this action is intended to achieve by itself. However, reclamation goals have been established and are expected to assist in achieving the following overall Cement Creek water quality expectations.

There is a locked gate at the site for access, which was installed to restrict public access, which has not been disturbed and there has been no indication of on-site camping or mechanical vehicular uses.

The AMD is currently being treated so this RAO is met if the treatment facility remains intact. This objective has been achieved with a high degree of confidence. Water quality monitoring at the site confirms that there is a reduction in heavy metal loading at the site.

Reduce or eliminate the generation of acidity from the mine drainage.

Samples of ground water and surface water data suggest a trend in reduction in COCs has occurred; however, the Removal Action Objective to reduce acidity appears not to be fully met. Measured pre-treatment pH went from 6.98 at the adit to 7.4 at the creek. Measured post-treatment pH went from 6.88 at the adit to 7.42 at the end of the treatment channel.

Since accurate pH measurements are difficult, and all these measurements are circum-neutral, these pH measurements do not indicate an issue.

Changes in dissolved metals in the water have been addressed by before-and-after water sampling of the area. There is data for analysis and current data shows trends in water quality improvement.

This objective, to date has been somewhat achieved. The treatment of the AMD has not significantly improved the pH of the AMD, but values are slightly higher at the channel as compared to at the adit. If anything, there is a mild improvement trend.

Reduce or eliminate metals loading to Cement Creek.

This removal action is anticipated to contribute to overall reductions in metal loadings in

Cement Creek to meet water quality standards, but would not singularly accomplish this goal. There are no numeric surface water or groundwater standards that this action is intended to achieve by itself. However, reclamation goals have been established and are expected to assist in achieving overall Cement Creek water quality expectations.

There is a locked gate at the site for access, which was installed to restrict public access, which has not been disturbed and there has been no indication of on-site camping or mechanical vehicular uses.

Recent Sampling Data – 2003-2010 sampling summary (17 adit and 13 channel sampling events)

Total Aluminum

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low .035 -.079 -232

High .071 .040 57

-38

Total Iron

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 10.9 6.3 58

High 18.8 8.0 42

Total Manganese

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 4.9 .558 11

High 7.6 1.6 21

Total Zinc

Low .520 .148 28

High .882 .176 20

Average total metal loading and reduction rates (lbs/day) for low and high adit discharge rates.

Values in bold represent overall heavy metal percent reductions. Negative values indicate an increase in

Dissolved Aluminum

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low .057 -.055 -99

High .249 -.002 -1

-89

Dissolved Iron

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 7.8 7.0 90

High 15.7 17.4 92

Dissolved Manganese

(lbs/day) Reduction at Outfall (lbs/day) % Reduction

Low 4.7 .591 13

High 7.5 1.8 24

Dissolved Zinc

Low .531 .271 51

High .933 .445 48

Average dissolved metal loading and reduction rates (lbs/day) for low and high adit discharge rates.

Values in bold represent overall heavy metal percent reductions. Negative values indicate an increase in

Again, there appears to be a 17-45% (total metals) and 20-93% (dissolved metals) reduction in Fe, Mn and Zn from the limestone-lined treatment channel and settling ponds.

Iron (Fe) is best adsorbed, while Aluminum (Al) actually showed an increase in loading along the treatment channel. Since Aluminum baseline concentrations are relatively low in this system, this is of minimal importance. Cadmium and copper loading and reduction rates were not analyzed because they had non-detectable concentrations according to laboratory analysis standards.

No distinct relationships between discharge rates and reduction potential were noted, indicating that contact time with substrate material may not be a limiting factor at this site.

Additionally, no clear trends were noted between time and load reduction, signifying that adit water chemistry is stable and/or the treatment system has not yet reached capacity.

There could be a relationship between algae coating and sludge on the limestone media and aeration of the AMD in the treatment channel which could affect the precipitation or reduction in the contaminants of concern.

The AMD is currently being treated so this RAO is met if the facility remains intact. This objective has been achieved with a high degree of confidence. Water Quality Monitoring at the site confirms that there is a reduction in heavy metal loading at the site.

Confine the action to the existing footprint.

This objective has been achieved. The treatment channel and ponds for treatment of the

AMD has been located in previously disturbed areas and is located adjacent to existing access.

Minimize operating and maintenance cost.

This objective has been achieved with confidence. The treatment of the AMD has been completed using affordable state of the art technology (2003) which required minimal maintenance costs. Operation since 2003 shows this to be a successful and effective treatment.

Reasonable Capital Cost.

This objective has been achieved with confidence. The initial design was based upon proven treatment methods. The treatment of the AMD has used technology which required minimal construction costs and currently requires minimal maintenance. Operation since 2003 shows this to be a successful and effective treatment..

Satisfy state and federal ARARS

ARARs were met. No numeric water quality standards need to be met on site.

This removal action is anticipated to contribute to overall reductions in metal loadings in

Cement Creek to meet water quality standards, but would not singularly accomplish this goal. There are no numeric surface water or groundwater standards that this action is intended to achieve by itself. However, reclamation goals have been established and are expected to assist in achieving overall Cement Creek water quality expectations.

CONCLUSION and RECOMMENDATIONS Based upon the qualitative assessment by BLM in Oct. 2014, the BLM considers the performance of the Elk Tunnel treatment to be currently performing as designed for the protection of human health and environment. BLM recommends the annual qualitative assessments be performed for the life of the project. A detailed quantitative assessment should be performed every 5 years, beginning in

2020.

Samples of surface water data suggest a reduction in COC’s has occurred; however, the quantification is only possible with minimal additional sampling and consideration of seasonal fluctuations. The sampling data will also assess the performance of the treatment media.

Continued sampling of the adit effluent and post treatment effluent should be completed on a 2-3 year cycle to compare with historic data, both pre and post treatment. This data can then be used to determine the effectiveness of the treatment and to determine the time frames for treatment media replacement or maintenance.

FUTURE ANNUAL MONITORING REQUIREMENTS

Annual physical monitoring of the site is needed for the life of the project to determine if the performance continues to remain satisfactory. Water samples should be evaluated every 2-3 years for the next 10 years (2025) to monitor treatment performance. After 2025, quantitative monitoring can be reduced to every 5 years (BLM-CO policy). Although the performance of the Elk

Tunnel treatment is satisfactory, yearly monitoring visual monitoring should be continued. The following is a list of monitoring that needs to continue. Attached to this report is a template which addresses the details needed for annual and 5 year monitoring efforts and documentation. Outside of those requirements the following will also need completion.

Every five years, the following should be inspected, documented and recorded in AMSCM:

1. Visual inspection for erosion to the site access and the site itself. Is any slumping occurring?

Are the gabion baskets still intact? Any erosion around the channels?

2. Inspect embankments/slopes for slumping, cracking, and rilling. Note areas of embankment slumping, rilling or character degradation.

3. Is the AMD and associated surface water control channels functioning? Is there evidence of erosion or pooling? Is drainage being successfully diverted away from the treatment areas?

4. Is the channel that contains the adit drainage from the tunnel functioning? Any major changes in the visual appearance of the water or the drainage channel itself? Is the geomembrane liner functioning? Is the liner still intact?

5. Is the area draining as designed? Run-on and run-off surface water control channels functional? Erosion an issue??

6. Is the gate designed to keep civilians and vehicles out functioning? Is there any evidence of on-site camping or mechanical vehicle uses?

7. Is signage (if applicable) still in place? Are there physical signs of recreation uses or visitation… camping, fire pits, etc.

8. If geomembrane liners are under the surface drainage or treatment channels, are they still intact? Exposed?? Extent of repair needed?

9. Adit water samples and channel outflow samples obtained to bracket passive treatment area. Any changes in physical characteristics? pH changes?

10. Bracketing Upstream and Downstream water quality samples in Cement Creek to insure treatment competency. A sampling plan including location and constituents shall be developed to obtain needed and complete data.

11. Benthic sampling and fish sampling should be integrated into the greater watershed monitoring plan.

12. As-built modifications noted? Maintenance noted? As applicable, does an explanation of significant differences exist in Close-out Report?? As this could alter the elements of a

PEMP.

13. Inspect perimeter for seepage or discoloration.

14. Changes in surrounding Land Use since the last inspection?

15. Ensure BLM’s Institutional controls are in force. For example, are LR2000 and Master Title

Plats updated showing the response action?

16. In addressing the effectiveness of this action, areas above and below disturbed sites should be monitored for water quality which would be used to assess the total effectiveness of those removal actions.

17. The Elk Tunnel adit water should be sampled for changes in chemistry, flow, pH and sediment load. Are there changes in the adit area?

18. Are the passive treatment channels and ponds performing as designed? Is the channel media working as designed? Would a different size media enhance buffering and has science changed significantly to re-evaluate the design.

19. It may be worthwhile to pump the ponds prior to the establishment of plant growth. Once the ponds become significantly full of muck and sludge, pumping should be initiated to see if maintenance costs (labor and equipment) can be reduced.

APPENDIX 1 – PERFORMANCE EVALUATION AND MONITORING PLAN OUTLINE

As of June 1, 2015 a PEMP has been prepared for each BLM CERCLA action within the State of Colorado.

And with that, BLM Institutional Controls have been entered into LR2000, the Master Title Plats (MTP), and the Historical Index (HI). Future CERCLA actions will also require the preparation of PEMPs. .

Because every response action is unique so should each PEMP; however, there are common elements and objectives in every CERCLA responses that should be considered in each PEMP. The following addresses the more common actions and highlights those elements that should be considered as universal and found in all PEMPs.

OUTLINE OF A PEMP

1. Introduction and background information – this section should provide a summary of the site, the overall problem, its COCs and risk(s), the response action and its RAOs. Most of this pertinent information is found in the EE/CA, RAM, RAO, PA, SI etc.

2. Performance Evaluation and Monitoring Plan – this is an overview of what has been done at the site to reduce or eliminate the recognized risks, what will be done at the site to evaluate the action’s performance and the time frames for it. It is recommended that detailed annual inspections be completed for the first 3-5 years after completion of the project, then on five year intervals. It will be a collaborative effort between the Field Office and the State Office to determine the extent of the monitoring effort.

This section should present the RAOs and what component of the response action is intended to satisfy that RAO, and how is this to be inspected and evaluated.

Specifically for the Remedial Action, the following will be addressed once the action has been implemented (generally a repository, bulkhead or passive treatment) and when it is determined that it is functioning as designed. For the first 3 to 5 years after construction, detailed qualitative yearly monitoring should be completed.

Every five years after the project is deemed functioning, the project should be inspected, documented and recorded in AMSCM.

The following are general examples that should be covered in the five year quantitative analysis and report – but will be modified using specific monitoring requirements as listed in the project specific

PEMP. See specific section “FUTURE ANNUAL MONITORING REQUIREMENTS” from the site specific

PEMP.

Repository

20. Check for revegetation density and diversity by completing vegetation transects on the repository. Inspect vegetation cover by using quantitated transect method to assess diversity and density of vegetation…. it may be decided that qualitative measures will be adequate.

21. Inspect embankments/slopes for slumping, cracking, and rilling. Note areas of embankment slumping, rilling or character degradation.

22. Is the surface channel functioning?

23. Is the area draining as designed? Run-on and run-off surface water control channels functional?

Erosion??

24. Is the fence (if applicable) designed to keep civilians and vehicles out functioning?

25. Is signage in place? Are there signs prohibiting recreation uses or visitation… camping, fire pits, etc.

26. Read groundwater wells located downgradient, as applicable, and note if performing as expected. This will require the piezometric surface elevation and may require analysis of water quality samples which will include COCs and total and dissolved metals.

27. If geosynthetic liners are used; are they exposed?

28. If trees are present, should they be removed? Refer to design specs for the project.

29. If a geoliner is present under the surface channel, is it still intact? Exposed??

30. Upstream and Downstream water quality samples to ensure repository competency. A sampling plan including location and constituents shall be developed to obtain needed and complete data.

31. Benthic sampling and fish sampling within the watershed.

32. If drains are present, are they functioning as designed (dry or running moisture?) If flowing, sample per above water quality protocols and also note flow rates and physical characteristics.

33. If Monitoring wells are present, measure depth to water and sample for COCs. PANs also require a comparison of these data to standards or other wells, intra well comparisons. .

34. As-built modifications noted? As applicable, does an explanation of significant differences exist in Close-out Report??

35. Inspect perimeter for seepage or discoloration.

36. Changes in surrounding Land Use since the last inspection?

37. Ensure BLM’s Institutional controls are in force. For example, are LR2000 and Land Plats updated showing the response action as applicable?

38. See specific section “FUTURE ANNUAL MONITORING REQUIREMENTS” from the PEMP

Bulkhead

1. Leakage around bulkhead and adjoining rock noted – flow quantity and quality. Sediment present?

2. Deformation around the bulkhead and portal area? Describe in detail.

3. Inspections of adjacent portal rock both for deformation and physical changes.

4. Quantity and quality of water - if flowing. A sampling protocol including location and constituents shall be developed to obtain needed and complete data.

5. Sand boils in d/s channel?

6. Sediment in d/s channel?

7. New seeps or springs?

8. Increased flow in existing seeps or springs?

9. Change in Land Use Planning adjacent to area?

10. Changes in technology?

11. Ensure BLM’s Institutional controls are in force. For example, are LR2000 and Land Plats updated showing the response action as applicable?

12. See specific section “FUTURE ANNUAL MONITORING REQUIREMENTS” from the PEMP

Passive Treatment

1. Time since last maintenance – is maintenance currently needed.

2. Condition of passive treatment material.

3. Water quality above and below treatment area. A sampling plan including location and constituents shall be developed to obtain needed and complete data.

4. Channel containment?

5. Changes since last inspection – treatment still appear functional?

6. Vegetation in treatment area – estimate percentage if yes – Issues?

7. Changes in technology for improved media material.

8. Is it functional or still needed?

9. Ensure BLM’s Institutional controls are in force. For example, are LR2000 and Land Plats updated showing the response action as applicable?

10. See specific section “FUTURE ANNUAL MONITORING REQUIREMENTS” from the PEMP

3. Five Year Reporting Requirements – Attached is a sample plan, also assuming the work has been contracted outside of BLM.

It is extremely important to report/document the conclusions of the monitoring efforts. There is no standard reporting format; however, it is critical that copies are placed in the case file and noted in

AMSCM.

The overall objective of reporting is to provide a documented conclusion as to whether or not the response action is achieving the RAOs. The performance assessment each RAO can be either qualitative or quantitative, but justified in the PEMP.

Monitoring and Maintenance Tasks – the tasks are the objectives for the CERCLA action to ascertain that the results are achieved and that the sites stay intact and functional.

General Objective – Include a short reiteration of the specifics of what and why we are monitoring and for how long.

Task 1. Inspection and repair of the soil or rock covers

Objective

Work Plan

The task will include:

1. Perform annual site inspections of surfaces in all disturbed areas by walking the surface of each repository;

2. Identify, map, and photograph any areas with erosion rills greater than 6 inches deep;

3. Direct repair of all erosion rills greater than 6 inches deep, and or subsidence, depressions, cracks or openings in the cover within 30 days of detection.

Site inspectors will perform visual inspections of soil surfaces of all soil and rock covered/reclaimed areas by walking the disturbed areas. The location and size of the identified erosion features requiring repair will be documented. Sites will be traversed in transects at a distance of approximately 50 feet apart to ascertain that the entire site is inspected. Soil erosion will be assessed using qualitative descriptors of soil surface status such as those identified in BLM form 7310-12 (BLM 19730).

Any areas of rilling exceeding 6 inches in depth will be identified, mapped with a Trimble GeoXH GPS receiver unit, or equivalent, measured, and photographed. A letter accurate GPS unit may be substituted if BLM determines accuracy needs are less stringent. Location, network, connectivity, and the potential for further erosion will be defined and documented for each problem location. All photographic and mapped documentation of identified information will be performed at sub-meter accuracy.

Repository soil and rock covers will also be visually inspected for signs of subsidence, which could be indicative of incomplete filling of voids or insufficient compaction. The location and dimensions of depressions, surficial cracks and fill slope bulges will be identified, documented as above, and reported

(including photo and mapping documentation) to the BLM. All depressions, cracks, or openings in the cover will be repaired within 30 days of discovery.

The run-on diversion channel of the repository will be visually inspected for excess erosion or sedimentation, subsidence, culvert breakage, HDPE issues etc., and riprap integrity.

Any deficiencies in soil cover noted during inspections will be documented in a letter report to the BLM.

Letter reports will include complete photographs and mapped documentation of any inspection, monitoring, or corrective actions, and will describe all findings, giving special attention to any problem areas or concerns requiring remedy.

All appropriate remedial repairs to correct any erosion problems on soil cover/reclaimed areas will be made within 30 days of inspection. A pre-qualified landscape contractor may be used for repair of erosional features, and to remove excess sediment from storm water control structures or the like, as necessary, and make any needed repairs to these structures. If weather conditions make repair and/or mitigation with 30 days impracticable, BLM will be notified within 10 days, with the understanding that

BLM will have the discretion to delay the repairs, until a time determined is practicable. All repaired areas will be re-seeded within 6 months, during the optimal seeding period, per discussion of reparative seeding, below.

All repairs and corrective measures will be documented in a letter report to the BLM within 30 days of the activity. Letter reports will include complete photographic and mapped documentation of the inspection, monitoring, and corrective actions, and will describe all findings. An index of the photographs will be provided, including GPS locations and direction view. Locations of all photographs and mapped documentation will be sub-meter in accuracy.

Task 2. Vegetative Monitoring and Weed Control

Objectives

The following General Revegetation Objectives will apply to the repository surfaces:

1. Within one year following seeding, viable, desirable seedling density or cover will be established on all repository surfaces. Seedling density or cover shall consist of a vigorous, diverse, native plant community as approved by the BLM Project Inspector (PI). Seeded vegetation will be of sufficient density or cover to ensure soil stability and minimize erosion.

2. By the fifth growing season, all repository surfaces will support a self-sustaining, vigorous, diverse, native (or otherwise approved) plant community with a density sufficient to control erosion and non‐native plant invasion.

Specific revegetation objectives for repository surfaces relative to weed cover and native vegetation diversity will be met as noted in the RAM, if applicable.

Work Plan: Vegetation Monitoring The task will include:

Annual quantitative revegetation monitoring of repositories, as applicable;

Annual qualitative monitoring of all other disturbed areas ‐ traverse with transects; ocular monitoring and at least 2‐3 photo points per site marked with rebar or fence post. Annual vegetation monitoring will be conducted during the period of peak vegetative production, typically mid‐July to mid‐August.

Repository covers may be sampled with quantitative methods, and all other disturbed areas will be subject to qualitative sampling methods.

If designated by BLM, Inspectors will sample repository covers using the point intercept method (Mueller‐ Dombois and Ellenberg, 1974). Data points will be sampled along parallel transects, stratified by slope. Transect locations will be established during the first annual vegetation sample event. If increases in plant species diversity are observed, additional transects may be added, as needed, in subsequent annual sample events. Each transect will be a minimum of 50‐meters long. Plant species will be documented as four or six letter codes, as applicable. Litter (dead remains of previous years’ plant growth), rock, or bare ground will be recorded, as appropriate, when no plant is intercepted at a sample point. Plant taxonomic authority will follow Weber and Wittmann (2012). A photo will be taken from fixed photo points located at the ends of each transect. Transect ends will be recorded using a Trimble GeoXH 3000 Series Global Positioning System (GPS) receiver unit (or as determined by BLM). These coordinates will be used to relocate transects for subsequent annual sample events. All photographs, plots, transects, points, and weed populations will be spatially referenced to a scale appropriate to the feature.

Descriptive statistics will be calculated for plant cover variables by transect, as well as for each repository cover. Cover variables will include: percent cover for each species as well as litter, rock, and bare ground categories. Descriptive statistics will include total cover by each cover variable; cover by non‐weed species; and cover by noxious weed species. Non‐native plants will be classified into the following subcategories: desirable, undesirable, noxious weed species to be controlled and other species to be controlled (DeYoung 2013).

Non‐repository covers, as applicable will be sampled qualitatively. Inspectors will traverse each site along parallel transects. Vegetation conditions will be noted and recorded. These will include: estimated percent cover by each dominant plant species; estimated cover by noxious weeds; and estimated total cover by desired plant species. General site conditions will also be recorded. Two or three photos will be taken from fixed photo points on each non‐ repository site. These photo points will be established during the first annual survey and referenced with a recorded GPS point.

Vegetation monitoring results will be presented and discussed in an annual monitoring report, submitted to BLM per description in Task 7, below. BLM may determine that data will also be entered into the BLM NISIMS database.

Work Plan: Weed Monitoring

Perform biannual (spring and summer) weed monitoring on all disturbed areas except shale removal slope;

Perform biannual weed control (with the exception of salt cedar) on all disturbed areas (10 acres or less per event).

Site inspectors will visual inspect the repository to determine presence of weeds annually (or more frequently, if directed by the BLM or determined to be necessary). Weeds to be controlled will include those non‐native species categorized as need‐to‐control” and all species listed on the State of Colorado Noxious Weed List. Findings of weed surveys will be documented to BLM in a letter report within 30 days of each inspection. Letter reports will include complete photographic and mapped documentation of the weed survey, and will describe all findings, giving special attention to any concerns requiring a remedy. All photographic and mapped documentation will be of sub‐meter accuracy.

Weed control activities (that may include mowing and/or herbicide application) at the appropriate time in the life cycle of the targeted weed to maximize control, will be completed as approved by BLM. A Pesticide Use Proposal (PUP) will be submitted to the BLM for approval prior to the application of herbicides.

Work Plan This task will include:

Seeding and re‐seeding, as approved by BLM, will be conducted to correct issues such as low percent cover of desirable native vegetation or other problems with achieving vegetation success criteria. Areas of significant bare soil identified will be re‐seeded, with BLM concurrence. Re‐seeding efforts will use site specific seed mix, developed with the Project PI. The seed mix will be reviewed annually to assess effectiveness and success rates by species, revegetation objectives, and erosion conditions. The seed mix may be changed with the approval of BLM to adjust to specific site conditions.

If bare areas persist after a second reseeding, representative soil samples from the bare areas and vegetated areas will be collected and analyzed to determine if small‐scale differences in nutrient status or physical properties may be responsible for lack of establishment of desired plant species.

Letter reports will include complete photographic and mapped documentation of seeding and re‐ seeding efforts, including seeding specifications, seed tags, and product submittals. All photographic and mapped documentation will be of sub‐meter accuracy.

Task 3. Surface Water Quality Monitoring Objective

Collect surface water data to determine if the remedy has had a positive impact on the surface water quality of the adversely affected Creek.

Work Plan The task will include:

Surface Water Quality Monitoring at designated sample sites: one sample site upstream of the repository; and 1 sample site downstream of the repository area. Rebar should be installed and a GPS location established to insure sampling occurs at the same location each year.

Sampling frequency of 1 sample event per year, if water is present in quantities sufficient to sample. No sampling in mid‐winter (i.e. Nov‐Jan). Any water quality exceedances will be reported to BLM immediately upon discovery.

Storm event sampling is not included in this plan. If requested by BLM, additional costs will be billed.

Grab samples will be collected from water sampling locations identified by BLM. Samples will be collected one time per year, between the months of February and October, when water is present in quantities sufficient to sample. If requested by BLM, samples will be collected after storm events. The sampling locations were determined in consultation with the BLM PI. These location coordinates were recorded with a GPS unit for use in future sample events.

These include:

(Sample location identified here – at this stage in the process – the FO will establish the locations concurrently with the BLM SO.)

Samples will be analyzed for:

dissolved metals by Environmental Protection Agency (EPA) Method 6010C and/or 6020A;

total recoverable metals by EPA Method 6010C and/or 6020A;

total mercury by 7470A;

volatile organic compounds (VOCs) by EPA Method 8260B;

semi‐volatile organic compounds (SVOCs) by EPA Method 8270C;

ammonia by Method 4500NH3 D;

sulfate, nitrate and nitrite by EPA Method 300;

total dissolved solids (TDS) by Method 2540C; and total suspended solids (TSS) by Method 2540D.

Volatile Organic Compounds (VOC) sample containers will be…