Pre-Treatment Water Quality in the Aaron Run Watershed

Transcription

1 DNR PPRP - 6 Pre-Treatment Water Quality in the Aaron Run Watershed May 3 PPRP i PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

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3 PRE-TREATMENT WATER QUALITY IN THE AARON RUN WATERSHED PREPARED FOR: POWER PLANT RESEARCH PROGRAM MARYLAND DEPARTMENT OF NATURAL RESOURCES PREPARED BY: LEONARD RAFALKO ROBIN LEE MAY 3

4 TABLE OF CONTENTS FOREWARD ACKNOWLEDGEMENTS ABSTRACT II III IV. INTRODUCTION. PROJECT OBJECTIVES. REPORT ORGANIZATION. SITE DESCRIPTION 3. WATERSHED DESCRIPTION 3. TREATMENT SYSTEMS DESCRIPTION 5 3. AMDL STUDY METHODS 7. WATER QUALITY EVALUATION. MINE DISCHARGE WATER QUALITY. STREAM WATER QUALITY 6.. Reach (Stream Location AH-) 9.. Reach (Stream Location AH-3) 9..3 Reach 3 (Stream Locations AH-5 and AA-) 9.. Reach (Stream Location AA-a) 3..5 Reach 5 (Stream Locations AA-3c, ST-, AA-, AA-5, and AA-6) 3..6 Reach 6 (Stream Location AA-7) 3 5. PRE-TREATMENT CONDITIONS AT AARON RUN AND WINDING RIDGE 3 5. SUMMARY OF THE WINDING RIDGE PROJECT 3 5. SUMMARY OF PRE-TREATMENT CONDITIONS AT WINDING RIDGE AND AARON RUN 3 6. SUMMARY REFERENCES 38 PPRP i PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

5 LIST OF FIGURES FIGURE FIGURE FIGURE 3 FIGURE AARON RUN WATERSHED REGIONAL VIEW WATER QUALITY SAMPLE LOCATIONS STREAM REACHES AND REPRESENTATIVE SAMPLE LOCATIONS PH AND FLOW RATE AT MINE DISCHARGE POINTS ALONG AARON RUN FIGURE 5 CONCENTRATION AND LOADING OF AMD INDICATOR PARAMETERS FOR MINE DISCHARGE POINTS ALONG AARON RUN FIGURE 6 PH AND FLOW RATE IN AARON RUN STREAM SAMPLES FIGURE 7 CONCENTRATION AND LOADING OF AMD INDICATOR PARAMETERS FOR AARON RUN STREAM SAMPLES FIGURE 8 FIGURE 9 FIGURE WINDING RIDGE PRE- AND POST-INJECTION DATA COMPARISON OF WINDING RIDGE PRE-INJECTION DATA TO AARON RUN MINE DISCHARGE DATA COMPARISON OF WINDING RIDGE PRE-INJECTION DATA TO AARON RUN MINE DISCHARGE DATA LIST OF TABLES TABLE TABLE AMLD MINE DISCHARGE SAMPLE DATA AMLD STREAM SAMPLE DATA APPENDICES APPENDIX A TIME SERIES PLOTS FOR AMLD SAMPLE LOCATIONS PPRP ii PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

6 FOREWARD In anticipation of completing major treatment systems impacting water quality in Aaron Run, a stream in Garrett County, Maryland, the Abandoned Mine Lands Division of the Maryland Department of the Environment (MDE AMLD) requested that the Maryland Power Plant Research Program make available its support contractor Environmental Resources Management, Inc. (ERM) to collect and consolidate available preconstruction water quality data for the stream to serve as a baseline for the project. ERM is PPRP s Environmental Engineering Integrator (EEI). The request also included a requirement to include comparison of the water quality of various discharges into Aaron Run with that from the Frazee Mine on Winding Ridge. The Frazee Mine, which is a small source of acid mine drainage (AMD) in Garrett County Maryland, was treated by injecting a grout mix of coal combustion by-products (CCBs) into the mine in 996. ERM s report was to include a section comparing the results achieved at Winding Ridge in terms of water quality, costs, and benefits at Aaron Run. Early observations and examination of records made it certain that given the terrain in the Aaron Run watershed together with the diversity of discharges and the absence of accurately geo-referenced maps of the prior mining activity; inmine treatment as performed at Winding Ridge would be cost prohibitive at Aaron Run. Thus the section on comparisons with Winding Ridge was limited to comparing water qualities. The AMLD completed construction of the treatment systems for Aaron Run during the time interval when preparation of this report commenced. The systems are operating and being maintained by AMLD. As such, this report collates the preconstruction water quality data to provide a basis for measuring the effectiveness of the AMD treatment systems. Paul Petzrick Maryland Power Plant Research Program PPRP ii PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

7 ACKNOWLEDGEMENTS This document has been prepared under the direction of Paul Petzrick at Maryland Department of Natural Resources, Power Plant Research Program. The project was a cooperative effort with the Maryland Department of the Environment Abandoned Mine Lands Division. Under contract to PPRP, this report was prepared by Robin Lee and Leonard Rafalko of Environmental Resources Management, Inc. in Annapolis, Maryland. PPRP iii PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

8 ABSTRACT In 9 the Maryland Department of the Environment Abandoned Mine Lands Division (AMLD) began construction of a series of combined passive and active treatment systems along Aaron Run, a Western Maryland Stream impacted by acid mine drainage (AMD). As the construction of the systems began, AMLD requested assistance from the Maryland Power Plant Research Program (PPRP) to document and evaluate the pre-treatment water quality data for Aaron Run. AMLD provided PPRP with the historic water quality for the stream and mine discharges. Under contract to PPRP, this report was prepared by Environmental Resources Management, Inc. (ERM) in Annapolis, Maryland. The quantity and quality of pre-treatment data for Aaron Run also provides an opportunity to discuss the differences in outcomes between different AMD treatment approaches. As such, this report also includes a brief discussion of the Winding Ridge project, which was PPRP s first demonstration project in which a grout made of CCBs was placed in a small coal mine in Western Maryland in an effort to reduce or eliminate the production of acid within the mine itself. Differences between the pre-treatment conditions at both sites (both physical and chemical) are considered. This report includes a compilation of the available pre-treatment water quality data for Aaron Run in both tabular and graphical formats, as well as a discussion of spatial trends in the water quality along the length of the stream. In addition, a brief review of the Winding Ridge project and a comparison of the pretreatment conditions at each site, and the challenges presented by each are included. PPRP iv PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

9 . INTRODUCTION The Maryland Department of Natural Resources (MDNR) Power Plant Research Program (PPRP) has prepared this report at the request of the Maryland Department of the Environment (MDE) Abandoned Mine Lands Division (AMLD). AMLD initiated a project to address acid mine drainage (AMD) in Aaron Run, a stream in Garrett County, Maryland that is listed on the state s 39(d) list of impaired waters because of the AMD impacts. In 9, AMLD began the installation of three treatment systems to address the AMD that discharges to Aaron Run from a number of mine openings within the watershed. By August 3, all portions of the treatment system had been completed. AMLD requested that PPRP collate and analyze the existing water quality data for the watershed and perform a pre-treatment assessment of the data. The pretreatment assessment presented herein provides a baseline for future evaluations of stream water quality once the treatment systems are all operational and postinstallation water quality data has been collected. As PPRP s Environmental Engineering Integrator (EEI), Environmental Resources Management, Inc. (ERM) performed the pre-treatment assessment and prepared this report under the direction of PPRP. This report also includes a summary of the approach used and water quality improvements achieved at another AMD-impacted site in Western Maryland. This project at Winding Ridge demonstrated the use of a grout consisting of percent coal combustion by-products (CCBs) to reduce the formation of AMD within a small underground coal mine (the Frazee Mine). The grouting approach demonstrated at Winding Ridge represents a technology for reducing or preventing the formation of AMD within the mine itself and could be used as an alternative or complement to treatment technologies like those installed at Aaron Run, which treat the AMD once discharged from the mine. Although the site details for Winding Ridge and Aaron Run differ, comparison of pre and posttreatment data for both sites offers a unique opportunity to evaluate the technology used at Winding Ridge compared with more traditional methods of treating AMD, such as those used at Aaron Run.. PROJECT OBJECTIVES AMLD s objective with the installation of the treatment systems is to mitigate the AMD-impacted stream waters of Aaron Run. The objectives of this pretreatment water quality assessment for the Aaron Run watershed are two-fold: Perform a comprehensive review and document the existing pre-treatment water quality data for the Aaron Run watershed so that the efficacy of the treatment systems can be evaluated; and PPRP PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

10 Discuss the similarities and differences between the pre-treatment water quality at the mine discharges along Aaron Run to the pre and post-injection mine discharge water quality at Winding Ridge. A grout mix consisting of CCBs and mine water were placed in Winding Ridge to reduce AMD.. REPORT ORGANIZATION The report is organized as follows: Section Site Description. Describes the physical setting of the Aaron Run watershed and the three treatment systems; Section 3 AMLD Study Methods. Describes the sampling locations and analyses performed by the AMLD to collect the pre-treatment water quality data at the mine discharges and within the stream at Aaron Run; Section - Water Quality Evaluation. Presents the existing pre-treatment water quality data for the mine discharges to Aaron Run and the surface water quality within Aaron Run and its tributaries; Section 5 Comparison of Pre-Treatment Water Quality at Aaron Run to Pre and Post-Injection Water Quality at Winding Ridge. Presents a comparison of the Aaron Run mine discharge data to the pre and post-injection water quality conditions at Winding Ridge; Section 6 Summary. Summarizes the findings of the pre-treatment water quality assessment for Aaron Run; Section 7 - References. PPRP PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

11 . SITE DESCRIPTION. WATERSHED DESCRIPTION Aaron Run is a tributary to the Savage River, which flows to the North Branch of the Potomac River (Figure ). Aaron Run extends approximately 3 miles from its headwaters to the confluence with the Savage River. The Aaron Run watershed covers approximately 3.5 square miles. Water quality in Aaron Run is impacted by AMD. Acidic water quality in the stream has been documented as far back as 966 (Baltimore District Corps of Engineers, 976). Additional studies of the Aaron Run watershed were performed in 989 and (PHR&A, 989; and University of Maryland, ); and confirmed AMD impact to the stream. The University of Maryland study was an assessment of the aquatic habitat and the benthic organisms present in Aaron Run. For this study, benthic macroinvertebrates and fish were collected and counted to assess the health of the stream habitat. The study also included an evaluation of the physical habitat and collection of water quality data. Water quality samples were analyzed for calcium, iron, magnesium, sulfate, aluminum, manganese, ph, specific conductivity, total suspended solids, total dissolved solids, acidity, and alkalinity. The benthic macroinvertebrate study concluded that the headwaters of Aaron Run had fair to good stream health scores but the scores declined significantly as tributaries that received mine discharge joined the main stem of Aaron Run. Thus, the University of Maryland study showed that the AMD discharging along Aaron Run was impacting the health of aquatic organisms in the stream. PPRP 3 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

12 Figure Aaron Run Watershed Regional View Aaron Run Watershed, Garrett County, Maryland Aaron Run Watershed Aaron Run Aaron Run Confluence with Savage River Savage River Confluence with North Branch of the Potomac River N Mile Source: USGS 7.5 minute Topographic Maps: Barton and Westernport Quadrangles

13 . TREATMENT SYSTEMS DESCRIPTION Prior to 9 there had been no AMD treatment or abatement performed for the Aaron Run watershed. In 9, AMLD began the installation of three treatment systems along the upper.5 miles of Aaron Run. The locations of the treatment systems are shown in Figure. The upstream most system is referred to as Aaron Run Stream Restoration. Moving downstream, the locations for the other two systems are referred to as Aaron Run Owens North and Aaron Run Owens South (Owens North and Owens South, respectively). The treatment systems consist of a combination of constructed wetlands and successive alkalinity producing system (SAPS) cells. The Aaron Run Stream Restoration system also includes a limestone doser. All three systems were in place and operating as of August. PPRP 5 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

14 Figure Water Quality Sample Locations Aaron Run Watershed, Garrett County, Maryland Aaron Run Stream Restoration AH- AH-3 3- AH- - AH-5A AH- - Aaron Run Owens North.3- AC- AC AA AA- 8- AH-5 Aaron Run Owens South AA-3 AA- AA-a ST AA-6 AA-5 - Legend - Mine Discharge Sample Location (AMLD Only) Surface Water Sample Location (BOM) Surface Water Sample Location (University of Maryland) Passive Treatment System Location.5-M N,5 Feet Source: USGS 7.5 minute Topographic Maps: Barton and Westernport Quadrangles AA-7

15 3. AMDL STUDY METHODS Between and 7, AMLD collected monthly water quality samples at a number of locations within the watershed. This dataset represents the most current analytical data for Aaron Run, and serves as the baseline for comparison with post-treatment data. AMLD collected samples of surface water from Aaron Run and some of its tributaries and samples of AMD directly from mine discharge points. Figure shows the AMLD water quality sample locations. All of the samples were analyzed for: Calcium; Iron; Magnesium; Sulfate; Aluminum; Manganese; Zinc; ph; Specific Conductivity; Temperature; Total Suspended Solids (TSS); Total Dissolved Solids (TDS); Acidity; and Alkalinity. Flow rate was also measured at most of the monitoring locations during some sampling events. Tables and present the analytical data for the AMLD mine discharge and stream water quality samples, respectively. PPRP 7 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

16 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Parameter Station ID Reach Number Reach 5/3/6 3/8/6 //6 /7/6 5/9/6 5/3/6 6/8/6 7/5/6 8//6 9/6/6 3/8/6 //6 /7/6 Major Ions Units NA NA Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate, ,53.,38.,7. Sulfate Load Trace Metals Aluminum < < Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm < Field ph S.U Sp. Cond. us/cm, ,9,8,79 Temp C TSS.. <. <. 9 <. 8 6 TSS Load TDS ,,7,9 TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AH- Reach AH- Reach 3 Page of 7

17 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Station ID Parameter Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AH- AH-a AH-b AH-c AH-5a AC- Reach 3 Reach 3 Reach 3 Reach 3 Reach 3 Reach 3 5/9/6 5/3/6 6/8/6 7/5/6 8//6 9/6/6 3/8/6 3/8/6 3/8/6 //6 3/8/6 // ,9.,55.8,93.7,85.,898., ,798.8,79.8,5.,78., ,5,53,93,97 3,38 3, 6,9 3,,8 3,5 3, ,83,87,6,,6,73 3,3,58,3,683, Page of 7

18 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Station ID Parameter Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AC- Reach 3 AC- Reach 3 /7/6 5/9/6 5/3/6 6/8/6 7/5/6 8//6 9/6/6 3/8/6 //6 /7/6 5/9/6 5/3/6 6/8/ ,77.6,789.,68,5., ,.8,896.8,79.9,68., ,3 3,7 3,69 3,7,,55,,, 3,38 3,65 3,9, < < ,6,687,68,79,96 3,38 33,8,935,59,6,53, Page 3 of 7

19 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Station ID Parameter Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AC- Reach 3 AA- Reach 7/5/6 8//6 9/6/6 3/8/6 /7/6 5/9/6 5/3/6 6/8/6 8//6 9/6/6 //6 /9/ ,7.9,66.3,37.,6.7,89.5,758.6,3.3,976.,6.7,7., ,6 3,9 3,65,39, 3,79,7,8 3,67,5, < ,787 3,38,955 3,55,86,755 3,398,8 3,535 3, 3, 3, Page of 7

20 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Station ID Parameter Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AA-3 Reach 5 AA-3a Reach 5 3/8/6 //6 /7/6 5/9/6 5/3/6 6/8/6 7/5/6 9/6/6 //6 /9/7 3/8/6 //6 5/9/ ,93.7, ,3.,9,636,7,97,36 88.,63.7,9., ,57 3,,,99,69 3, 3,3 3,6 3,3,8,38,9 3, < ,53,63,53,83,777,38,65,996,88,3 3,89 3,, Page 5 of 7

21 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Station ID Parameter Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AA-3a AA-3b Reach 5 Reach 5 5/3/6 6/8/6 6/5/6 8//6 9/6/6 //9 /9/7 3/8/6 //6 /7/6 5/9/6 5/3/6 6/8/6 NA ,83.,7.,753.8,5.6,6.,687.,.5,96.,8.,567.,56., ,36,6,7,9 3,9,,,7,39 3,,5 3, < < ,38,89 3,8 3,3 3,67 3,57,76,93,87,398,8, Page 6 of 7

22 Table AMLD Mine Discharge Sample Data Aaron Run Watershed, Garrett County, MD Station ID Parameter Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NA - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed AA-3b Reach 5 8//6 9/6/6 /9/7 NA ,3.8, ,8, ,55, Page 7 of 7

23 Table AMLD Stream Sample Data Aaron Run Watershed, Garrett County, MD Parameter Station ID Reach Number 3/8/6 //6 /7/6 AH- Reach Major Ions Units Calcium Calcium Load Iron < < Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum <. <. <. <. <. <. <. <. <. <. <. <. <. <. Aluminum Load Manganese <.3 <.3 <.3 <.3 < <.3. <.3.9 <.3. Manganese Load Zinc <.3..7 <.3 <.3 <.3.5 <.3. <.3.. <.3. Zinc Load Other Flow gpm , Field ph S.U Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NS - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed. - Samples at location AA-7 collected on /8/, 5/5/5, and 6//5 were collected from within the Savage River downstream of the confluence with Aaron Run. The sample collected on //5 was collected from within Aaron Run just upstream of the junction with the Savage River. AH-3 Reach 5/9/6 5/3/6 6/8/6 7/5/6 8//6 9/6/6 //6 //5 //5 /5/5 //5 Page of 5

24 Table AMLD Stream Sample Data Aaron Run Watershed, Garrett County, MD Parameter Station ID Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NS - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed. - Samples at location AA-7 collected on /8/, 5/5/5, and 6//5 were collected from within the Savage River downstream of the confluence with Aaron Run. The sample collected on //5 was collected from within Aaron Run just upstream of the junction with the Savage River. AH-3 Reach AH-5 Reach 3 AA- Reach 3 /9/6 //5 3/8/6 //6 /7/6 5/9/6 5/3/6 6/8/6 7/5/6 8//6 9/6/6 //6 //5 5/3/ ,58,56.9, < < < < , ,6, ,57,76 ---,8 3,,7,3, < ,9,5 79 3, ,87,36,6,685, AA-a Reach AA-3c Reach 5 Page of 5

25 Table AMLD Stream Sample Data Aaron Run Watershed, Garrett County, MD Parameter Station ID Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NS - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed. - Samples at location AA-7 collected on /8/, 5/5/5, and 6//5 were collected from within the Savage River downstream of the confluence with Aaron Run. The sample collected on //5 was collected from within Aaron Run just upstream of the junction with the Savage River. AA-3c Reach 5 6/8/6 7/5/6 8//6 9/6/6 /9/7 3/8/6 //6 5/9/6 5/3/6 7/5/6 8//6 9/6/6 //6 /9/ NS NS NS NS NS NS NS NS ,3.5,86,73., NS NS. <. <. <. <..68 <. < NS NS NS NS <.3 < ,6 NS NS 5 ---,73,85,6 3,9 3,57 3, 3, NS NS NS NS ,6 NS NS ,3,386,6,76,67,59, NS NS NS NS ST- Reach 5 Page 3 of 5

26 Table AMLD Stream Sample Data Aaron Run Watershed, Garrett County, MD Parameter Station ID Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NS - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed. - Samples at location AA-7 collected on /8/, 5/5/5, and 6//5 were collected from within the Savage River downstream of the confluence with Aaron Run. The sample collected on //5 was collected from within Aaron Run just upstream of the junction with the Savage River. AA- Reach 5 /8/ 5/5/5 6//5 //5 8//6 //6 /9/ NS NS NS ,5., ,.3, ,96. NS, <. <. <. <. <. <. <. NS <. < NS.6 < < <.3 <.3.6 NS <.3 < ,9,5,7 3,,5, 3,9 NS,8, NS < 39 NS ,6,85,59,9,968,57,396 NS,69, NS NS AA-5 Reach 5 3/8/6 //6 /7/6 5/9/6 5/3/6 6/8/6 7/5/9 Page of 5

27 Table AMLD Stream Sample Data Aaron Run Watershed, Garrett County, MD Parameter Station ID Reach Number Major Ions Units Calcium Calcium Load Iron Iron Load Magnesium Magnesium Load Sulfate Sulfate Load Trace Metals Aluminum Aluminum Load Manganese Manganese Load Zinc Zinc Load Other Flow gpm Field ph S.U. Sp. Cond. us/cm Temp C TSS TSS Load TDS TDS Load Acidity Acidity Load Alkalinity Alkalinity Load Notes NS - Not Sampled < Not detected, value indicates detection limit Blank cell indicates that parameter was not analyzed. - Samples at location AA-7 collected on /8/, 5/5/5, and 6//5 were collected from within the Savage River downstream of the confluence with Aaron Run. The sample collected on //5 was collected from within Aaron Run just upstream of the junction with the Savage River. AA-6 Reach 5 3/8/6 /7/6 5/9/6 5/3/6 6/8/6 7/5/6 8//6 9/6/6 //6 /9/7 /8/ 5/5/5 6//5 //5 See Note <.3.9 < ,73.3,67.5, <. <. <. < <.3 < <.3 <.3 < , ,569,35,86,6,9,6, < < ,6 8, ,86,79,66, AA-7 Reach 5 Page 5 of 5

28 . WATER QUALITY EVALUATION Water quality data for the mine discharge points that flow into Aaron Run and the stream water quality within Aaron Run are discussed separately in Sections. and. of this report, respectively. For ease of discussion and simplicity in comparing the eventual post-treatment data to the pre-treatment data, PPRP has subdivided Aaron Run into five stream reaches for this report. The stream reaches, shown in Figure 3, are defined by the occurrence of mine discharge points and the locations of the treatment systems. Reach Upstream of all mine discharges and treatment systems. o Mine discharge sample locations: none. o Stream sample locations: AH-. Reach Downstream of first mine discharge, but upstream of all treatment systems. o Mine discharge sample locations: and AH-. o Stream Sample Locations: AH-3. Reach 3 Downstream of first mine discharge and Aaron Run Stream Restoration treatment system, but upstream of the Owens North and Owens South treatment systems. o Mine discharge sample locations: AH- (a, b, c), AH-5a, AC-, and AC-. o Stream sample locations: AH-5 and AA-. Reach Downstream of Aaron Run Stream Restoration and Owens North treatment systems, but upstream of Owens South treatment system. o Mine discharge sample locations: AA-. o Stream sample locations: AA-a. Reach 5 Downstream of all mine discharges and treatment systems, but upstream of confluence with the Savage River. o Mine discharge sample locations: AA-3 (a b). o Stream sample locations: AA-3c, ST-, AA-, AA-5, and AA-6. Reach 6 Downstream of all mine discharges and treatment systems at the confluence of Aaron Run with the Savage River o Mine discharge sample locations: none. o Stream sample locations: AA-7. PPRP PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

29 Figure 3 Stream Reaches and Representative Sample Locations Aaron Run Watershed, Garrett County, Maryland Aaron Run Stream Restoration AH- AH- AH-3 AH- AH-5A Reach : Upstream of all Discharges and Systems Stream: AH- Reach : Downstream of first Discharge, Upstream of Stream Restoration System Discharge: : AH- Stream: AH-3 AC- AC- AA- AH-5 Reach 3; Downstream of Stream Restoration System, Upstream of Owens North and Owens South Systems Discharge: AH-; AC-; AC- Stream: AH-5; AA- Aaron Run Owens North Aaron Run Owens South AA- AA-a AA-3 (ab) AA-3c AA- ST- AA-6 AA-5 Reach : Downstream of Stream Restoration and Owens North Systems, Upstream of Owens South System Discharge: AA- Stream: AA-A Reach 5: Downstream of all Discharges and Systems Discharge: AA-3(ab) Stream: AA-3 ; ST-; AA-; AA-5, AA-6 Reach 6: Confluence with Savage River Stream: AA-7 Legend Mine Discharge Sample Location (AMLD Only) Surface Water Sample Location (BOM) Surface Water Sample Location (University of Maryland) Passive Treatment System Location N,5 Feet Source: USGS 7.5 minute Topographic Maps: Barton and Westernport Quadrangles AA-7

30 . MINE DISCHARGE WATER QUALITY Aaron Run receives mine discharge from a total of known discharge points: (Reach ) AH- (Reach ) AH-a AH-b Sampled collectively as AH- (Reach 3) AH-c AH-5a (Reach 3) AC- (Reach 3) AC- (Reach 3) AA- (Reach ) AA-3a Sampled collectively as AH-3 (Reach 5) AA-3b The water quality data available for all of the mine discharge monitoring points is presented in Table. Figure summarizes the ph and flow rate of the mine discharges by stream reach. Figure 5 summarizes the concentration and loading of key AMD indicator parameters at the mine discharges by stream reach. Appendix A presents time series plots for all of the monitored parameters. As shown in Figure, the average flow rates of the mine discharges range from approximately gallons per minute (gpm) to gpm. The exception to this observation is discharge point in Reach. AMLD recorded a flow rate of 5 gpm at this location on 3 May 6, which was the only date that this location was monitored. The other mine discharge location in Reach is AH- where flow reported by AMLD ranged from less than gpm to gpm. Excluding discharge, individual flow rates for a specific monitoring event ranged up to 9 gpm, which was reported for AA-3 in Reach 5. The water quality of the mine discharges varies between stream reaches. In general, the average ph values ranged from.6 to.5, other than at discharge point. The concentrations and loadings of iron, sulfate, and acidity varied by approximately orders of magnitude across the stream reaches. At discharge point, AMLD recorded a ph value of 6.6, by far the highest of any ph values reported by AMLD at a mine discharge location. The ph at AH- in Reach ranged from 3.3 to.9. The only notable alkalinity produced from any of the mine discharges was recorded by AMLD at. PPRP PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

31 Figure ph and Flow Rate at Mine Discharge Points Along Aaron Run Aaron Run Watershed, Garrett County, Maryland ph Flow 7 ph (s.u.) Reach Reach 3 Reach Reach 5 Flow (gpm) 5 Reach Reach 3 Reach Reach 5 5 AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b Aaron Run Sample Location Aaron Run Sample Location Range Average ph vs Flow Rate Flow Rate (gpm) AH- AH- AH-A AH-B AH-C AH-5A AC- AC- AA- AA-3 AA-3a AA-3b Note: Locations and AH- are not shown on this figure as the ph (6.6, >6.) and flow rate (5 gpm at ) are much higher than other locations. ph (s.u.) Note that Reach is upstream of all mine discharge, and is presented as a reference point.

32 Figure 5 Concentration and Loading of AMD Indicator Parameters for Mine Discharge Samples Along Aaron Run Aaron Run Watershed, Garrett County, Maryland Fe () 5 Iron Concentration Reach Reach 3 Reach 5 Fe () 5 3 Reach Iron Load Reach 3 Reach Reach 5 5 Reach AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b Aaron Run Sample Location Aaron Run Sample Location 3 Sulfate Concentration 3 Sulfate Load SO () Reach Reach 3 Reach Reach 5 SO () Reach Reach 3 Reach Reach 5 AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b Aaron Run Sample Location Aaron Run Sample Location Acidity Concentration Acidity Load Acidity () 8 6 Reach Reach 3 Reach Reach 5 Acidity () 3 Reach Reach 3 Reach Reach 5 AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b AH- AH- AH-a AH-b AH-c AH-5a AC- AC- AA- AA-3 AA-3a AA-3b Aaron Run Sample Location Range Average Aaron Run Sample Location

33 In general, the AMD emanating from discharge points located closest to the Aaron Run headwaters within Reaches and 3 has higher ph values and lower levels of acidity and iron than the AMD emanating from the discharge points located further downstream within Reaches and 5. Figure shows that ph trends downward from a high value of 6.6 at discharge location in Reach to a ph value of less than 3 in Reach 5. Overall, the ph of the AMD emanating from the mine discharges gradually decreases with distance downstream along Aaron Run. The concentrations and loadings for iron, sulfate, and acidity are shown in Figure 5 for each mine discharge location. Iron and acidity concentrations and loadings clearly increase downstream from Reaches and 3. Regarding iron, its loading in Reaches and 3 are generally less than five pounds per day (lbs/day), while farther downstream, at Reaches and 5, iron loadings have exceeded 5 lbs/day at discharge locations AA- and AA-3. A similar observation between Reaches and 3, and Reaches and 5 can be made for acidity. Sulfate is somewhat more variable than iron and acidity, and shows a rather gradual increase in concentration within Reach 3, leveling out within Reaches and 5 at a maximum recorded loading of approximately, lbs/day at AA-3. The water quality of AMD can fluctuate significantly with flow rate. In some cases, higher flow rates dilute acidic discharge, leading to higher ph values at higher flow rates. In other cases, higher than usual flow rates dissolve secondary salt (i.e. sulfate and sulfite mineral) deposits and can cause slugs of low ph and elevated acidity and metals. Accordingly, the ph of the mine discharges (excluding discharge ) was plotted in Figure against flow rate to determine whether there appears to be a relationship between flow rate and concentrations of AMD parameters. The data for the Aaron Run discharges show different relationships between ph and flow at different discharge points. Discharge points AH- and AA-3 show fairly large ranges in flow rate but the ph observed at these locations stays constantly within a relatively narrow range. Conversely, discharge points AH-, AC-, and AC- show a slight tendency toward higher ph at higher flow rates. Based on the average water quality and flow rates data at the mine discharges, it is estimated that these discharges introduce a combined total of over, gallons of AMD with an average ph of 3.6 into Aaron Run each year. The average loading rates indicate that the discharge also introduces approximately tons of iron, 867 tons of sulfate, 5 tons of aluminum, 58 tons of acidity, and, tons of total dissolved solids to Aaron Run annually. The locations of the three treatment systems are positioned at three different mine discharges. The location of the uppermost treatment system, Aaron Run Stream Restoration, is positioned at AH- in Reach 3. AH- is the first mine discharge to show ph values below. and acidity values above. The PPRP 5 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

34 Owens North and Owens South locations are positioned at AA- in Reach and AA-3 in Reach 5, respectively. These locations have some of the lowest ph values measured in the mine discharges and some of the highest concentrations and loadings of iron, sulfate, and acidity. The placement of the Owens North and Owens South treatment systems addresses the most downstream mine discharge locations identified by AMLD.. STREAM WATER QUALITY AMLD collected samples of stream water from the main stream of Aaron Run and from certain tributaries at locations: AH- (Reach ) AH-3 (Reach ) AH-5 (Reach 3) AA- (Reach 3) AA-a (Reach ) AA-3c (Reach 5) ST- (Reach 5) AA- (Reach 5) AA-5 (Reach 5) AA-6 (Reach 5) AA-7 (Reach 6) The stream water quality data are presented in Table. Time series plots of AMLD stream samples are presented in Appendix A. Figure 6 summarizes the ph and flow rate data for the stream sampling locations by stream reach. Figure 7 summarizes the concentration and loadings of key AMD indicator parameters at the stream sample locations by stream reach. It should be noted that flow rate data were not available for every sampling event at every stream location, thus flow rates could not be plotted or loadings calculated for every sample date. PPRP 6 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

35 Figure 6 ph and Flow Rate in Aaron Run Stream Samples Aaron Run Watershed, Garrett County, Maryland ph Flow 8 7 Reach Reach Reach 3 Reach Reach 5 Reach Reach Reach Reach 3 Reach Reach 5 Reach 6 ph 6 5 Flow (gpm) AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location Range Average Indicates a tributary, rather than the main stem of Aaron Run. 3 5 AH- AH-3 AH-5 AA- ph vs Flow Rate Flow Rate (gpm) 5 AA-a AA-3c ST- AA- AA-5 AA-6 AA Locations AA and AA5 are located on tributaries rather than the ph Note that Reach is upstream of all mine discharge, and is presented as a reference point. Note: AA-7 data from //5 was not included in the graphs because the sample for this date was collected from a different location from the previous samples.

36 Figure 7 Concentrations and Loadings of AMD Indicator Parameters for Aaron Run Stream Samples Aaron Run Watershed, Garrett County, Maryland 3 Iron Concentration Iron Load Fe () 5 5 Reach Reach Reach 3 Reach Reach 5 Reach 6 Fe () 5 Reach Reach Reach 3 Reach Reach 5 Reach AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location Sulfate Concentration 3 Sulfate Load SO () 5 Reach Reach Reach 3 Reach Reach 5 Reach 6 SO () 5 5 Reach Reach Reach 3 Reach Reach 5 Reach AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location Acidity Concentration Acidity Load 5 Acidity () 3 Reach Reach Reach 3 Reach Reach 5 Reach 6 Acidity () 8 6 Reach Reach Reach 3 Reach Reach 5 Reach 6 AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 AH- AH-3 AH-5 AA- AA-a AA-3c ST- AA- AA-5 AA-6 AA-7 Aaron Run Sample Location Aaron Run Sample Location Range Average Indicates a tributary, rather than the main stem of Aaron Run. Note: AA-7 data from //5 was not included in the graphs because the sample for this date was collected from a different location from the previous samples.

37 Overall, the water quality begins at near neutral ph with low concentrations of acidity, iron, and sulfate in the upper reaches of Aaron Run (Reach and ). The ph decreases and concentrations of acidity, iron, and sulfate increase as the stream receives flow from the mine discharges along Reaches 3,, and 5, with the most degraded water quality occurring within Reach 5. By the time Aaron Run reaches its confluence with the Savage River (Reach 6) the ph has improved to near-neutral levels and concentrations of iron, acidity, and sulfate have decreased. A detailed description of the water quality within each reach of Aaron Run is given below... Reach (Stream Location AH-) Reach is the segment of Aaron Run that is upstream of all mine discharges and passive treatment systems; as such, it represents the background water quality of Aaron Run, unimpacted by AMD. As expected for an unimpacted stream segment, the data for Reach shows a near neutral ph (average 6.7), lower concentrations of iron and sulfate compared to downstream values, and very low acidity (Figures 6 and 7). As shown in Table, most of the samples for Reach contained alkalinity, rather than acidity. Table also shows that concentrations of aluminum, manganese, and zinc (metals which are also commonly elevated in AMD) are very low compared to downstream locations or non-detect. The ph of this stream reach does not vary with flow rate (Figure 6)... Reach (Stream Location AH-3) Reach is the segment of Aaron Run that is downstream of the first mine discharges to enter the stream ( and AH-) but upstream of all of the treatment systems. The water quality does not show significant AMD impacts, although this reach contains mine discharge. The ph level and concentrations of iron, acidity, sulfate as well as aluminum, manganese, and zinc for stream water in this reach are comparable to the same parameters within upstream Reach (Figure 6 and 7 and Table ). Review of the data for the mine discharges contained within this reach (mine discharge and AH-) shows that the AMD at these discharges is marginal compared to typical AMD water quality: the ph is above., the concentrations of iron and acidity are relatively low, and only one of the mine discharges () has elevated levels of sulfate...3 Reach 3 (Stream Locations AH-5 and AA-) Reach 3 is the first segment of Aaron Run which is downstream of any treatment system components (Aaron Run Stream Restoration and a limestone doser). Reach 3 also contains the largest number of mine discharge points [AH- (A, B, and C), AH-5a, AC-, and AC-]. This is the first reach of Aaron Run to show notable AMD impacts. The average ph of this reach ranges from about.5 to about 6. Although iron and acidity concentrations are relatively low, the sulfate concentration is elevated to approximately 8 milligrams per liter () PPRP 9 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3

38 (Figures 6 and 7). In addition, aluminum, manganese, and zinc are detected consistently at both stream monitoring locations, albeit at relatively low levels (Table ). These results are consistent with expectations given the quality of the mine discharge within this reach. Within Reach 3, mine discharge ph ranged from 3 to 3.5, acidity and sulfate concentrations were approximately, and,5, respectively (iron concentrations are still relatively low) (Figures and 5); in addition, the mine discharges show elevated levels of aluminum, manganese, and zinc (Table )... Reach (Stream Location AA-a) Reach is downstream of the second treatment system (Owens North). In addition to one stream location, this reach also includes one mine discharge location (AA-). The stream ph within this reach is comparable to Reach 3 at about 5 (Figure 6) but the concentrations of iron, sulfate, and acidity are significantly higher than observed upstream within Reach 3 (Figure 8). The data for the mine discharge point (AA-) shows that the AMD entering Aaron Run within this reach is similar in ph to the Reach 3 mine discharges, but contains significantly more iron and acidity. Concentrations of aluminum, manganese, and zinc are elevated in the Reach stream and mine discharge samples compared to the Reach 3 stream and mine discharge samples...5 Reach 5 (Stream Locations AA-3c, ST-, AA-, AA-5, and AA-6) Reach 5 contains the last of the known mine discharge points (AA-3, AA-3a, and AA-3b) along Aaron Run. At first glance, the stream water quality within Reach 5 appears to be highly variable: the ph ranges from to 6.5, average iron concentrations range from less than to over 3, average sulfate ranges from to over,, and average acidity ranges from nondetectable to 5 (Figures 6 and 7). Concentrations of other trace metals (aluminum, manganese, and zinc) are similarly variable (Table ). It should be noted, however, that Reach 5 contains multiple types of stream water samples. Sample location ST- is a sample from an unnamed tributary to Aaron Run that is collected at the confluence of the two streams. Sample location AA-5 is a collected from the outfall of a pond at the Owens South treatment system location. Although both of these stream samples show evidence of AMD impact (primarily in the form of elevated sulfate concentrations), the ph, iron, and acidity levels at ST- and AA-5 show much less AMD impact than the other Reach 5 stream sample locations. It is likely that ST- and AA-5 are receiving additional unimpacted stream water, diluting the impact of the AMD discharges. The water in the pond may also be under more reduced conditions, which tend to reduce the severity of AMD impacts. Notwithstanding the variability of results at the different stream sample locations within Reach 5, the overall stream water quality within Reach 5 is PPRP 3 PPRP/AARON RUN PRE-TREATMENT REPORT-MAY 3