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HomeMy WebLinkAbout03-23 Hydrogeologic Report An Equal Opportunity Employer M/F/V/H Date: September 25, 2023 To: Lindsey Marhefka, Carmeuse Americas Logan Thompson, Carmeuse Americas From: Mark J. Krumenacher, GZA GeoEnvironmental, Inc. Stephanie A. Cook, P.G., GZA GeoEnvironmental, Inc. Bernard G. Fenelon, GZA GeoEnvironmental, Inc. File No.: 20.0158489.00 Re: Site Conceptual Hydrogeologic Model Existing Quarry and Proposed New Quarry Carmeuse Winchester Quarry Winchester, Virginia GZA GeoEnvironmental, Inc. (GZA) is pleased to provide O-N Minerals (Chemstone) Company, d/b/a Carmeuse Americas (Carmeuse/“Client”) this site conceptual hydrogeologic model (“Report”) for the Winchester Quarry (“Existing Quarry”) and nearby property to the north in Frederick County, Virginia (“Site”) where Carmeuse is proposing a new quarry development as an expansion of the Existing Quarry (“Proposed Quarry”). The Existing Quarry, Proposed Quarry, and several former quarries between the two locations are referred to collectively as the “Quarry Area” or “quarries,” each shown on Figure 1. EXECUTIVE SUMMARY 1. During almost 70 years of bedrock mining (quarrying) in the area, the available technical evidence does not support that the pumping of water out of the mine/quarry (dewatering) has impacted nearby springs, streams, ponds, or water supply wells with the possible exception of a 14-foot hand dug well. The evidence that supports this conclusion includes the continued existence of local springs, ponds, streams, and water supply wells near the former and Existing Quarry and the lack of documentation that these resources have experienced problems associated with the quarries. If the opposite were true, there would be ample documentation developed over the decades showing otherwise. 2. The historic and Existing Quarry provides a decades old living laboratory that can be used to predict the potential impact the Proposed Quarry may have on surface water and groundwater, albeit to a lesser degree due to its proposed shallower depth of excavation. 3. The existing quarrying in the Martin Pit will have less potential to impact nearby groundwater users because it will be mined 160 feet shallower than the adjacent East Pit that was mined for several decades. By mining shallower, the groundwater level in and immediately adjacent to the Martin pit will remain at least 160 feet higher than in the East Pit while it was mined and the water was pumped out. 4. Given that water pumping from the East Pit had no reported impact on the nearby springs, streams, ponds, and potable water supply wells, it is reasonable to conclude that 160 feet shallower mining in the adjacent Martin Pit will also not impact those resources. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 2 Proactive by Design 5. Groundwater level data from wells installed near the Existing Quarry show little impact of quarry dewatering on the groundwater elevations. A residential well located about 300 feet west of the Martin Pit shows water levels 150 feet higher than the quarry floor, indicating very little drawdown in the aquifer and a very limited cone of depression to the west. Similarly, groundwater level data from a monitoring well installed about 600 feet north of the East Pit shows groundwater to be at least 140 feet higher than in the East Pit water level as of September 2023, indicating very little drawdown in the aquifer and a very limited cone of depression to the north. The favorable geologic structure (bedrock dip and faulting) that minimizes the groundwater drawdowns west and east of the Quarry Area is evidenced by the flowing springs and streams, ponds, and productive water supply wells located east and west of the quarries. 6. Mining in the Proposed Quarry will also lower the groundwater level in the pit to about 300 feet below the surrounding ground surface, like at the Martin Pit, but similarly is not expected to impact nearby springs, streams, ponds, and potable water supply wells due to the same geologic settings. 7. History has demonstrated that quarrying in the area has not negatively affected the surface water and groundwater resources and will provide for a long-term reliable source of potable water in addition to providing the needed construction aggregate for the rapidly growing County. 8. The two major bedrock types in the area, mapped as carbonate (limestone) and shale (which includes limestone and sandstone), provide the area with a reliable source of domestic potable water that has not been negatively affected by the previous or existing, quarrying. 9. Although a relatively widespread phenomenon in the carbonate bedrock of the Shenandoah Valley, sinkhole formation in the Frederick County area is of relatively minor occurrence. Almost 70 years of mining have not exacerbated sinkhole formation and because of the similar geologic conditions with the Existing Quarry, the risk of enhanced sinkhole formation with the Proposed Quarry is expected to similarly be low. 10. GZA’s review of recent surface water and well complaints alleging impacts from quarrying indicate that, with the exception of a 14-foot deep almost 200-year-old hand dug well approximately 200 feet from the Existing Quarry, quarry dewatering is not the cause of the alleged complaints. 11. GZA reviewed Carmeuse’s Rezoning Proffer Statement submitted July 2023, and in particular Section 8 “Ground Water” which offers repairs to damage caused by mining to water supply wells on Surrounding Property, defined to be within 1,500 feet of the Proposed Quarry property. Based on the size of the Proposed Quarry property, the well protection will extend up to 2,500 feet west, up to 5,000 feet east, up to 3,500 feet north, and up to 5,500 feet south of the proposed extraction area (the quarry) within the Proposed Quarry Property. Based on our understanding of the hydrogeologic model as described in this Report, Carmeuse’s commitment to the County and the surrounding community is greater than the potential impact and industry standard of care for this geologic setting and the proposed scale of operation. PURPOSE We understand that Frederick County representatives requested that Carmeuse address potential water quantity and quality impacts to potable water supply wells in response to County representatives and citizen questions raised during public discussions on the Proposed Quarry. GZA has extensive experience evaluating surface water and groundwater at quarries similar to Carmeuse in Virginia, nearby states and elsewhere across the United States. We understand the potential impact that mining can have, as well as the depth of federal, state, and local rules, regulations, guidance, and best management practices that mining operations need to follow. As professionals, GZA serves as an independent third party that relies solely upon verifiable, vetted, technical facts. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 3 Proactive by Design INTRODUCTION GZA developed the conceptual hydrogeologic model for Carmeuse and other stakeholders to describe the physical conditions and characteristics of the geology and the surface water-groundwater interactions as they relate to natural conditions, and those that may be associated with past, present, and proposed limestone bedrock mining in the area. This Report is intended to answer questions and concerns that the County and other stakeholders may have pertaining to potable water supply wells, springs, and streams in the area. Note that our conceptual hydrogeological model is subject to the Limitations provided in Attachment 1. GZA is a multidisciplinary engineering, environmental and geologic consulting firm founded in 1964. GZA now has about 700 staff in 32 offices across the US. The GZA staff identified above are licensed professional geologists in multiple states, including Virginia, have combined 100 years of hydrogeologic experience and are providing technical opinions as they pertain to the hydrogeology of the region and Quarry Area as experts in mining properties, practices, and operations; and the physical characteristics and interactions of mining on soil, bedrock, surface water, groundwater and earth science by knowledge, skill, experience, training, and education. GZA was requested to review the Existing Quarry and Proposed Quarry operations and independently opine on the degree and extent of potential impacts quarrying has had or may have on the regional and local hydrogeology that includes springs, ponds, streams and groundwater. GZA geologists familiarized themselves with the hydrogeologic conditions in the Existing Quarry and Proposed Quarry vicinity, historical mining and groundwater use, and performed a reconnaissance of the area, quarries, springs, streams, and ponds. GZA also reviewed and considered water supply well and surface water complaints that were recently raised at public meetings and addressed those at the end of this Report. On September 20, 2023, Mr. Krumenacher visited and observed the Existing Quarry (East Pit, Martin Pit, Pit #1, Pit #2, and Pit #3); the Proposed Quarry property; Whetzel spring location; and nearby streams (Turkey Run, Clear Brook Run, and Opequon Creek. During the September 20, 2023 visit, Mr. Krumenacher had no restrictions on access to the pertinent areas or limitations on time and had opportunity to observe areas of interest. Information obtained from the site visit included observations that were consistent with GZA’s independent research and review and the findings and conclusions presented in this Report. The information reviewed by GZA during preparation of this Report included, but was not limited to the following: • 1894, re-issued 1899, United States Geological Survey (USGS) Winchester W VA.-VA. Sheet 1:125,000 topographic map; • 1966, USGS 1:24,000 Quadrangle, Inwood, W. VA. – VA.; • 1966, USGS 1:24,000 Quadrangle, Inwood ,W VA. – VA., photo revised 1979, photo inspected 1984; • 1966, USGS 1:24,000 Quadrangle, Stephenson, W. VA.; • 1966, USGS Quadrangle, Stephenson, W. VA., photo revised 1978; • 1966, USGS 1:24,000 Quadrangle, Stephenson, W. VA., photo revised 1987; • 2014, 2017, 2019, and 2021 aerial photographs, Frederick County GIS Planning Access Terminal; • 1985, through 2023 aerial photographs on Google Earth Pro; • U.S. Drought Monitor1 https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?VA; 1 The U.S. Drought Monitor is produced through a partnership between the National Drought Mitigation Center at the University of Nebraska- Lincoln, the United States Department of Agriculture and the National Oceanic and Atmospheric Administration. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 4 Proactive by Design • 1962, Metcalf, Robert W., Calver, James, and Dorchak, Victoria M., Bureau of Mines, U.S. Department of the Interior and Virginia Division of Mineral Resources, The Mineral Industry of Virginia; • 1967, Drake Jr., Avery Ala and Epstein, Jack B., USGS, The Martinsburg Formation (Middle and Upper Ordovician) in the Delaware Valley Pennsylvania-New Jersey, Contributions to Stratigraphy, Geological Survey Bulletin 1244-H; • 1977, July, Hinkle, Kenneth R., and Sterrett R. McChesney, Shenandoah County Groundwater, Present Conditions and Prospects, Planning Bulletin 306; • 1986, November, Sweet, Palmer C., Virginia Department of Mines, Minerals and Energy, Virginia Minerals, Vol 32, No. 4, Virginia’s Lime Industry; • 1986, Fichter, Lynn S., and Diecchio, Richard J., Geological Society of America Centennial Field Guide—Southeastern Section, The Taconic Sequence in the Northern Shenandoah Valley, Virginia; • 1996, Hollyday, E.F., and Hileman, G.E., USGS, Hydrogeologic Terranes and Potential Yield of Water to Wells in the Valley and Ridge Physiographic Province in the Eastern and Southeastern United States, Professional Paper 1422-C; • 2004, Swain, Lindsay A., Mesko, Thomas O., and Hollyday, Este F., USGS, Summary of the Hydrogeology of the Valley and Ridge, Blue Ridge, and Piedmont Physiographic Provinces in the Eastern United States, Professional Paper 1422- A; • 2005, Harlow, Jr., George E., Orndorff, Randall C., Nelms, David L., Weary, David J. and Moberg Roger M., USGS, Hydrogeology and Ground-Water Availability in the Carbonate Aquifer System of Frederick County, Virginia, Scientific Investigations Report 2005-5161; • Undated, Doctor, Daniel H., USGS, Mapping Sinkholes and Areas of Surface Water--Groundwater Interaction in Relation to Geologic Structure; • 2003, Orndorff, Randall C., Weary, David J., and Parker, Ronald A., USGS, Geologic Map of the Winchester Quadrangle, Frederick County, Virginia; • 2006, Weary, David J., Orndorff, Randall C., and Aleman-Gonzalez, Wilma, USGS, Geologic Map of the Stephens City Quadrangle, Clarke, Frederick and Warren Counties, Virginia, USGS Open File Report OF-2006-1173; • 2022, Weary, David J., Doctor, Daniel H., Orndorff, Randall C., USGS, Geologic Map of the Stephenson Quadrangle, Frederick and Clarke Counties, Virginia, and Jefferson County, West Virginia; • 2022, Weary, David J., Doctor, Daniel H., Orndorff, Randall C., USGS, Geologic Map of the Inwood Quadrangle, Berkeley and Jefferson Counties, West Virginia, and Frederick and Clarke Counties, Virginia; • 1994, Orndorff, Randall C. and Goggin, Keith E. USGS, Sinkholes and Karst-Related Features of the Shenandoah Valley in the Winchester 30' X 60' Quadrangle, Virginia and West Virginia; • Virginia Department of Energy, Geology Mineral Resources sinkhole map, GIS-based website: https://energy.virginia.gov/webmaps/GeologyMineralResources/; • 1987, Virginia Department of Mines, Minerals and Energy, Division of Mineral Resources, Geologic Map of Virginia; • Virginia Administrative Code Title 12, Health Agency 5, Department of Health, Chapter 590. Waterworks Regulations Part II. Operation Regulations for Waterworks; • 2000, November, Science Applications International Corporation (SAIC), Hydrogeologic Evaluation Whetzel Spring Supply Well, Frederick County, Virginia; September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 5 Proactive by Design • 2000, May 17, SAIC, Log of OW-1-31E; • 2000, May 22, SAIC, Log of SW-1-26 (Whetzel Spring Well); • Undated, Frederick Water, Anderson Water Treatment Plant Well Monitoring; • 2018, 2019, 2020, 2021, 2022, 2023, Frederick Water, Anderson Well Data; • Frederick Water, Service Area Map, https://www.frederickwater.com/; • Berkely County Public Service Water District, Service Area Map, West Virginia, https://www.berkeleywater.org/; • NELUP-Plan A website Get Involved | Nelup Plana (nelup-plana.org); • Carmeuse core hole summary data; • 2020, 2021, 2022, 2023, Carmeuse groundwater monitoring well water elevation data; • 2018, 2019, 2020, 2021, 2022, 2023, Carmeuse water pumping data; • September 8, 2023, telephone interview with a local water well driller; and • September 20, 2023, Quarry Area reconnaissance. CONCEPTUAL HYDROGEOLOGIC MODEL The depth of information reviewed and researched by GZA as summarized above was relied on to some extent and informed on the preparation of this Report. As presented below, the above sources were utilized to develop an understanding of the hydrogeologic characteristics of the area and present facts on the history of quarrying in the area; ground surface topography; surface water features such as springs, ponds, and streams; the soil types; the bedrock structure and characteristics of the local limestone and shale; groundwater occurrence and movement; past, current and proposed quarry dewatering; area groundwater use; and review of recent complaints pertaining to surface water and water supply wells. QUARRY HISTORY 1. A 1986 Virginia Department of Mines, Minerals and Energy report (Sweet, 1986)2 states that “W. S. Frey Company, Inc., located about 7 miles north of Winchester in Frederick County, just east of Clear Brook, has been in operation at this site since 1961.” 2. An October 22, 2022 story in the Winchester Star (Carmeuse reveals future plans for its Clear Brook location) states that quarrying in the area was occurring in the 1950s, which may have intended to state 1960s. The report indicates that a tunnel was constructed beneath Brucetown Road that Carmeuse reports was in the 1960s, to allow passage between the initial two mine pits, Pit #1 and Pit #2, shown on Figure 1. 3. Local quarrying also occurred in the early 1960s, approximately 1 mile southwest of the Carmeuse property, on land now owned by the Frederick County Sanitation Authority, now Frederick Water, where depicted on Figure 1. 4. Sweet, 1986 reported at least 5 other limestone mining locations in Frederick, Shenandoah and Rockingham counties, indicating a long history of limestone mining in the area. 5. USGS Quadrangle maps show that Pit #1, Pit #2, and a portion of the processing plant area on the Carmeuse property were active in 1967, Pit #3 was active in 1979, and the East Pit was active in 1987. These pits and plant area are shown on Figure 1. 2 1986, November, Sweet, Palmer C., Virginia Department of Mines, Minerals and Energy, Virginia M inerals, Vol 32, No. 4, Virginia’s Lime Industry. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 6 Proactive by Design 6. Carmeuse reported that the Martin Pit (Figure 1) commenced development in 2018 as confirmed by aerial photographs reviewed on Google Earth and the Frederick County GIS Planning Access Terminal. 7. The Martin Pit is the only Carmeuse pit that is actively being mined at the time of this Report. Each of the other former quarries identified above are flooded or being flooded with water. 8. Frederick Water utilizes Pit #1 and Pit #2 as a potable water supply sources, pumping about 2 million gallons per day (MGPD) and recharges the pits using two water supply wells (OW-1-31E at 0.5 MGPD and Whetzel Well 1 MGPD) installed in 2000 about 500 and 1,300 feet from Pit #2, respectively. The Frederick Water supply well locations are shown on Figure 1. TOPOGRAPHY AND SURFACE WATER 9. The Existing Quarry and Proposed Quarry are located in the Shenandoah Valley region of the Valley and Ridge Physiographic province characterized by a repeating series of ridges (mountains) separated by valleys formed from lateral forces that folded the bedrock strata. 10. The nearest ridges are North Mountain located about 5 miles west and Blue Ridge about 15 miles east of the Existing Quarry and Proposed Quarry, as shown on Figure 2. 11. The ground surface generally slopes east from elevations greater than 1,000 feet on the ridges to an elevation of about 465 feet at Opequon Creek about 2.5 miles east of the Quarry Area. 12. The Existing Quarry and Proposed Quarry properties are at approximate elevation 620 feet, midway between the western ridges and the valley bottom at Opequon Creek. 13. In the Quarry Area, surface water flows east to Opequon Creek in a relatively closely spaced series of streams, from less than ½-mile to 1 mile apart, many of which emanate from springs located from less than 1 to 2 miles west of the Quarry Area. The springs and streams are shown on Figure 3. 14. The springs near the Quarry Area are generally at ground surface elevation of 600 to 700 feet, providing an indication of the groundwater elevation at those locations. 15. The streams near the Quarry Area are mapped as intermittent and/or perennial. Where perennial, which also provides an indication of groundwater elevation, the approximate elevations range from 600 to 700 feet. 16. The streams and several of the springs are mapped on the USGS Quadrangle maps dating back to 1899 and are shown on maps prepared in each decade since. 17. The springs and streams have been draining surface water and groundwater since the ridges and valley formed and local development, including quarrying, has not materially altered the flow patterns. 18. During mining of each of the quarries in the area identified above and on Figure 1, groundwater and surface water that accumulated in the quarry was temporarily pumped, as is ongoing in the Martin Pit, but after mining and pumping stopped, the quarries filled with water. 19. The water elevation in the filled quarries is indicative of the groundwater elevation at those locations, similar to the springs, groundwater fed ponds, and perennial streams in the area. GEOLOGY Soil 20. The soil in the area mapped by the United States Department of Agriculture (USDA) Natural Resource Conservation Service (NRCS) was formed from the weathering of the underlying bedrock. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 7 Proactive by Design 21. At and east of the Existing Quarry, the soil is primarily mapped as channery loam 18 to 33 inches thick over bedrock. Channery denotes the soil contains more than 15% by volume flat fragments of bedrock as long as 6 inches in dimension. 22. West of the Existing Quarry and at the Proposed Quarry, where the underlying bedrock is limestone, the soil is comprised of greater than 80 to 90 inches of clay, the maximum depth of investigation by the NRCS. 23. East of the Proposed Quarry, the soil is also primarily mapped as channery loam 18 to 33 inches thick over bedrock (shale). 24. The soil formed as the product of chemical and mechanical weathering of the underlying bedrock and reflects the physical characteristics of the rock from which it was formed. Thus, the soil that formed from the weathering of limestone and shale is fine-grained clay and silt. 25. Because the bedrock east of the Quarry Area also contains sandstone and conglomerate, the soil may also contain sand and gravel-sized particles. Bedrock 26. The bedrock in the Shenandoah Valley is geologically divided into two primarily rock types, carbonate (limestone) at and west of the Quarry Area and the Martinsburg Formation, rock regionally referred to as shale with layers of limestone and graywacke (clayey sandstone with a range of grain sizes) east of the Quarry Area. 27. The carbonate bedrock in the area includes the New Market Limestone, the target rock quarried by Carmeuse, and the overlying Edinburg Limestone and underlying Rockdale Run Formation. 28. The bedrock overlying the Edinburg Limestone is the Martinsburg Formation, commonly referred to as a shale which also includes limestone and sandstone. 29. The Existing Quarry and the Proposed Quarry are located along the eastern margin of the carbonate bedrock area where limestone is the surficial rock. The limestone is present from the quarry properties to at least 1 to 2 miles west beyond the nearest ridges described above. 30. Bedrock geologic maps with locations of the prior, existing, and the Proposed Quarry highlighted are included as Attachments 2 and 3. 31. The bedrock in the region is folded, forming the valley and ridge topography described above and as shown in the cross-sections included on the geologic maps. 32. In the region that includes the Quarry Area the bedrock dips generally east at about 45 degrees. 33. Similarly, in the area of Opequon Creek and areas east, the bedrock dips generally west at about 45 degrees. 34. The east and west dipping bedrock form a syncline (Massanutten Synclinorium), a linear trough, with an axis located about halfway between the quarry areas and Opequon Creek, as shown on the geologic maps. 35. The limestone that is mined at the Existing Quarry and proposed to be mined at the Proposed Quarry (the New Market Limestone) is less than 250 feet thick, but due to the relatively steep dip, may be exposed at the ground surface in relatively thin bands 250 to 500 feet wide; which is why the limestone quarries are generally long and narrow but can be deeper than 250 feet. 36. The limestone is overlain by the Martinsburg Formation, generally referred to as shale. In the Quarry Area, the shale is absent or thin, but from the eastern margins of the quarry areas to Opequon Creek, the shale is shown on the geologic map cross-sections to be more than 3,000 feet thick. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 8 Proactive by Design HYDROGEOLOGY The groundwater system in the region is principally in the underlying bedrock. The overlying soil is thin and fine-grained, so is not anticipated to provide suitable water storage for domestic use. Limestone 37. The limestone is dense and fine-grained and saturated where present below the groundwater table surface. 38. Based on the elevation of springs and perennial streams near the quarries, and the soil thickness, the groundwater elevation is generally at or near the top of bedrock. 39. The five springs located in the Quarry Area (Hot Run spring head water, Washington, Turkey Run head water, Whetzel, and Branson) range in elevation from 590 feet (Whetzel) to 650 feet (Washington). The spring and stream locations are shown on Figure 3. 40. A small unmapped spring was also reportedly present on the southern end of the Martin Pit but that areas was recently excavated in accordance with state permits. 41. The USGS reported that many springs in the Shenandoah Valley “are associated with faults, suggesting that faults may serve as important directional controls on ground-water flow.” 42. Although saturated, the limestone’s dense, fine-grained matrix will store and transmit very little groundwater and is similar in character to dense concrete. 43. Photographs included in Attachment 6 taken in Pit #1 and the Martin Pit show the typical character of the limestone bedding and jointing and dry nature of the quarry walls. 44. The groundwater storage and transmission (flow) in the limestone is in the joints derived from bedding planes (spaces between rock layers) and fractures that formed in response to the forces that caused the bedrock layers to fold. A schematic showing the conceptual groundwater flow in fractured carbonate bedrock is provided in Attachment 4. 45. The joints are ubiquitous throughout the limestone and trend in parallel and perpendicular directions relative to each other and generally transmit water where present below the groundwater table. 46. In some areas when the bedrock is resistant to folding, the forces cause the rock to break along a fault plane moving rock upward or downward sometimes distances of hundreds of feet relative to the other side of the fault plane. The faults are not always a single, thin plane, but a series of parallel faults and fractures (fault zone) over hundreds of feet that can emanate for long distances (miles). Major faults are commonly included on the USGS geologic maps. A fault located between the Martin Pit and the East Pit is evident on the geologic map and cross- section in Attachment 3. 47. Joints in limestone bedrock may maintain an aperture (separation) that can provide a path for groundwater to be transmitted vertically downward within the bedrock and horizontally from higher to lower elevations where it discharges to surface water. 48. Other joints may be characterized by or be partially filled with broken rock that can be subject to dissolution by mildly acidic precipitation and recharge water and erosion by flowing water. 49. These fractures provide the groundwater migration pathways from recharge, water that infiltrates the ground, and enable the groundwater to flow from higher elevations to lower elevations discharging into the area streams (Hot Run, Clearbrook Run, Turkey Run, Coyle Run, Duncan Run, and others). Streams are highlighted on Figure 3. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 9 Proactive by Design 50. Each of those streams transmit precipitation runoff and groundwater and ultimately discharge into Opequon Creek. 51. Water supply wells installed in the limestone rely upon the bedrock joints to transmit water to the well and, where joints are infrequent, need to rely on the open well borehole to store water due to the low rate of groundwater recharge to the well. 52. Based on a review of the Frederick Water distribution map and aerial photographs, there appear to be nine residential or commercial buildings that may have limestone wells in the vicinity (within 1 mile) west of the Existing Quarry, assuming other area buildings within the areas of the municipal water distribution systems are connected to municipal water, which may not be the case. Limestone is only present north, south, and west of the Existing Quarry. 53. Outside of the Frederick Water and Berkeley County, West Virginia distribution systems, aerial photograph review identified approximately 10 residences ¾- to 1 mile west of the Proposed Quarry where limestone is mapped. 54. The Frederick Water distribution area and location of residences and commercial businesses within a 1-mile radius of the East Pit are shown on Figure 4. 55. The Frederick Water and Berkeley County distribution areas and location of residences and commercial businesses within a 1-mile radius of the Proposed Pit are shown on Figure 5. 56. Based on GZA’s discussion with a local water well driller, water supply wells that are installed in the limestone that is generally present north, south, or west of the Quarry Area are completed to depths of 200 to 500 feet. 57. Streams generally form in areas of weak rock caused by joints and faults, characteristics that can extend to great depths. 58. Karst features formed by the dissolution of carbonate (limestone) bedrock may result in sinkhole formation. 59. Sinkhole occurrence is mapped by Virginia Department of Energy, Geology Mineral Resources with data plotted on a GIS-based website: https://energy.virginia.gov/webmaps/GeologyMineralResources/. 60. Sinkholes are present throughout the band of carbonate bedrock present in the Shenandoah Valley, but occur at a relatively low density as compared to the remainder of the valley in Frederick County, as shown on the figures in Attachment 5. 61. The low density of sinkhole formation in the Quarry Area during more than 70 years of mining indicates that there is a low risk of future sinkhole development with the Proposed Quarry that will be shallower with less dewatering than the Existing Quarry. 62. One relatively active sinkhole is reportedly present in the vicinity of Turkey Run north of the Proposed Quar ry. Anecdotal evidence from the local landowner/farmer is that the sinkhole has been forming there for decades and is filled with rock and soil when it opens. Shale 63. The bedrock present east of the Quarry Area to Opequon Creek is the Martinsburg Formation. See Geologic Maps in Attachments 2 and 3. 64. The Martinsburg is present along an approximately 3-mile wide, north-south valley that extends through the Shenandoah Valley. 65. The Martinsburg is reported by the USGS (online spatial data) to be predominantly shale with scattered limestone and sandstone interbeds, particularly in the lower section. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 10 Proactive by Design 66. Rader and Biggs, 1976,3 reported that the Martinsburg contains three general rock types; a lower section of shale and limestone, a middle flysch sequence (thin beds of shale or marl with sandstone or conglomerate), and an upper sandstone. 67. Harlow et al.,4 reported that the Martinsburg consists of interbedded shale and lesser graywacke siltstone and graywacke sandstone and define the basal unit as the Stickley Run Member comprised of platy limestone and calcareous shale. 68. Images of the three Martinsburg rock types taken from Google Earth Street View are provided in Attachment 6. 69. The term shale is used to denote rock comprised of fine-grained sediment smaller than sand in the range of silt to clay (finest). Shale, also commonly referred to as mudstone, ranges from siltstone to claystone, none of which may be comprised purely of silt or clay, but a gradational mixture, and may include a broad percentage of sand. 70. Near the quarries, the lower shale and limestone are likely present, which are described further as argillaceous (shaley) limestone and calcareous (limey) shale.5 See images of lower Martinsburg shale in Attachment 6. 71. Further east, halfway to Opequon Creek and toward the axis of the syncline (Massanutten Synclinorium), the flysch deposits and sandstone may be present. See images of the middle flysch and upper sandstone of the Martinsburg in Attachment 6. 72. Harlow et al., reported that the top of the Martinsburg (the sandstone) is not present in Frederick County. 73. The Martinsburg was studied in adjacent Shenandoah County (Hinkle and Sterrett, 1977)6 where it is present in the same physiographic and geologic setting as in Frederick County. 74. Hinkle and Sterrett reported that the Martinsburg is the best groundwater-producing formation in the County, as good as the limestone, and also reported good to excellent well yields when overlain by alluvial deposits (in the area of streams). 75. The Martinsburg bedrock has several physical features that apparently makes it a reliable groundwater source. The rock is in a folded, fractured, and faulted trough structure. The Martinsburg also contains limestone and calcareous shale layers that can be subject to dissolution resulting in groundwater transmission pathways. The Martinsburg also contains sandstone layers and, as shown in Attachment 6, is highly jointed, which provides groundwater storage and increased bedrock permeability. 76. Streams generally form in areas of weak rock caused by fractures and faults, characteristics that extend to great depths vertically. 77. The USGS geologic map in Attachment 3 includes an audiomagnetotellurics apparent electrical resistivity section along a portion of the cross-section that depicts the subsurface near the Existing Quarry. 78. Apparent electrical resistivity surveys in bedrock are used to identify and distinguish, on a broad scale, between competent bedrock (high apparent resistivity) and permeable bedrock (low apparent resistivity) that are jointed and fractured. 3 Rader, Eugene K., and Biggs, Thomas H., 1976, Geology of the Strasburg and Toms Brook Quadrangles, Virginia: Virginia Divisio n of Mineral Resources, Report of Investigations 45. 4 Harlow, Jr., George E., Orndorff, Randall C., Nelms, David L., Weary, David J. and Moberg Roger M., 2005, U.S. Geological Survey, Hydrogeology and Ground-Water Availability in the Carbonate Aquifer System of Frederick County, Virginia, Scientific Investigations Report 2005-5161. 5 Fichter, Lynn S., and Diecchio, Richard J., 1986, The Taconic Sequence in the Northern Shenandoah Valley, Virginia, Geological Society of America Centennial Field Guide—Southeastern Section. 6 Hinkle, Kenneth R., and Sterrett, R. McChesney, July 1977, Groundwater of Shenandoah County, Virginia, Valley Regional Office Virginia State Water Control Board Bureau of Water Control Management, Planning Bulletin 306. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 11 Proactive by Design 79. The apparent electrical resistivity survey shows that the central portion of the area mapped with the Martinsburg, centered on the axis of the Massanutten Synclinorium, exhibits a low apparent electrical resistivity indicative of saturated permeable bedrock to great depths. 80. Based on GZA’s conversation with a local water well driller, water supply wells are installed in the shale at depths of 200 to 600 feet and typically produce 5 to 10 gallons per minute (gpm) and can produce up to 20 gpm. 81. Hinkle and Sterrett reported that the water quality in the shale is similar to that in the limestone, although it is not as hard and contains higher than average iron and manganese concentrations that are greater than state and federal drinking water standards. 82. Water quality in shale commonly contains minerals that may impart odor, color, or sediment in the water. A local well driller told GZA that the water from the shale commonly contains high iron, sulfur, and other minerals. 83. Outside of the Frederick Water distribution system, aerial photograph review identified 54 residences or commercial buildings within a 1-mile radius of the Existing Quarry that likely have wells installed within the shale. Those wells are generally ¼- to 1 mile from the Existing Quarry. 84. Outside of the Frederick Water and Berkely County, West Virginia distribution systems, aerial photograph review identified 57 residences or commercial buildings within a 1-mile radius of the Proposed Quarry that likely have wells installed within the shale. Those wells are generally ½- to 1 mile from the Proposed Quarry. 85. The Frederick Water and Berkely County, West Virginia water distribution area and location of residences and commercial businesses within a 1-mile radius of the Proposed Quarry are shown on Figure 5. 86. Commonly, limestone and shale would be considered two hydrostratigraphic units, the limestone an aquifer and the shale a confining layer or aquitard. 87. Based on the physical characteristics of the Martinsburg described above and evident in photographs contained in Attachment 6, such as low- and high-angle joints, faults, and granular layers (flysch and sandstone), it is reasonable to consider the limestone and shale in the Quarry Area to be one hydrostratigraphic unit, or one aquifer. 88. Harlow et al., focuses on the carbonate aquifer that overlies the Martinsburg, and do not describe the Martinsburg as a distinctly separate aquifer or as an aquitard. 89. Although one hydrostratigraphic unit, the Martinsburg likely contains localized confining layers where joints are not as prevalent; however, those areas would be localized and not have a major influence on the overall transmission of groundwater in the region. Examples of that condition are evident in photographs of the Martinsburg lower unit in Attachment 6. HISTORICAL AND CURRENT QUARRY DEWATERING 90. Quarry dewatering has been ongoing in the Quarry Area since at least the 1960s. 91. The dewatering rate at each of the quarries is not known and is anticipated to be a function of the quarry size and depth. 92. Quarry pumping data provided by Carmeuse for the East Pit ranged from about 0.6 to 1.4 MGPD (400 to 1,000 gallons per minutes [gpm]) and averaged about 1.0 MGPD (700 gpm). The broad range in pumping data is due in part to variations in flow estimating that are based on pump curves, pumping elevations and piping lengths and drought conditions. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 12 Proactive by Design 93. The estimated surface water drainage area into the East Pit is about 135 acres. Based on the average annual precipitation of 42 inches per year, the average annual precipitation contribution to the annual pumping from the East Pit was about 0.4 MGPD, (300 gpm), or about 30% to 70% of the total water pumped from the quarry. 94. The estimated groundwater pumped from the East Pit ranged from 0.2 to 1.0 MGPD (150 to 700 gpm), in the range of pumping rates reported by Frederick Water from their two production wells at the Anderson Treatment Plant. 95. Quarry pumping data provided by Carmeuse for the Martin Pit for 2018 through 2023 ranged from about 0.6 to 0.7 MGPD (450 to 500 gpm). 96. The estimated surface water drainage area into the Martin Pit is about 60 acres. Based on the average annual precipitation of 42 inches per year, the average annual precipitation contribution to the annual pumping from the Martin Pit was about 0.2 MGPD (130 gpm), or about 30% of the total water pumped from the quarry. 97. The estimated groundwater pumped from the Martin Pit ranged from 0.4 to 0.5 MGPD (300 to 350 gpm), less or equivalent to the lower capacity pumping well utilized by Frederick Water at the Anderson Treatment Plant. 98. Little to no groundwater was observed by GZA entering the walls of Pit #1, Pit #2, Pit #3, the East Pit and Martin Pit, which is consistent with the low pumping rates reported by Carmeuse (see photographs in Attachment 6). 99. In GZA’s experience, the estimated groundwater withdrawal rates less than 1,000 gpm are very low for a carbonate bedrock quarry where rates as high as 20 to 30 MGPD or 15,000 to 20,000 gpm may occur. 100. Data available to predict the rate of quarry filling is from the East Pit, where groundwater pumping ended in late 2021, and water elevations measured by Carmeuse indicate the East Pit had filled with more than 230 feet of water by September 7, 2023; an average rate of about 750,000 gallons per day. 101. The observed average rate of East Pit filling with precipitation and groundwater is consistent with the estimated pumping rates from the quarries. 102. The geology of the various quarries is similar, so it is reasonable to believe that the historical dewatering rates since the early 1960s were consistent with the current dewatering rates at the Existing Quarry. 103. Quarries that were dewatered and then reflooded naturally with groundwater include the now County-owned quarry about 1 mile southwest of Carmeuse, Pit #1, Pit #2, Pit #3, and the East Pit. In each quarry, except the East Pit, which is still reflooding, the groundwater level returned to pre-dewatering elevations. 104. The water levels in the local springs, streams, and ponds provide the most relevant and reliable evidence of the impact of local quarry dewatering on the groundwater table surface. 105. The position of the Quarry Area and high density of springs, streams, and ponds in the folded regional bedrock trough fed by groundwater recharge from nearby ridges and thin soil over jointed and faulted generally permeable bedrock make the variety of permanent water features the surface expression of groundwater. 106. During the history of quarry dewatering, it is reasonable to believe, anecdotally (due to lack of documentation or reports to the contrary which would be expected), and based on a review of aerial photographs, that the local springs kept flowing; these include the following: a. Hot Run spring headwater located approximately 2,600 feet from the East Pit and 2,000 feet from the Martin Pit; b. Washington Spring located approximately 4,600 feet from the East Pit and 3,900 feet from the Martin Pit; c. Slate Run spring headwater located approximately 1,500 feet from Pit #1 and 1,300 feet from Pit #2; September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 13 Proactive by Design d. Whetzel Spring, located approximately 500 feet from Pit #3 and 1,400 feet from Pit #2; and e. Turkey Run spring headwaters located approximately 500 feet from Pit #3. 107. During the history of quarry dewatering, based on the same premise as with the springs that the streams kept flowing; these included the following: a. Hot Run located approximately 300 feet from the East Pit; b. Clearbrook Run located approximately 300 feet from the Martin Pit and East Pit before dewatering water is added to it near the East Pit; c. Slate Run located approximately 1,500 from Pit #1 and 1,300 feet from Pit #2; and d. Turkey Run located approximately 3,000 feet from Pit #3. 108. During the history of quarry dewatering, based on the same premise as with the springs, the nearby ponds retained their water; these include the following: a. The pond fed by Hot Run spring located approximately 750 feet from the East Pit and 900 feet from the Martin Pit; b. Two unnamed ponds along Hot Run located approximately 600 and 900 feet south of the East Pit, respectively; c. Clearbrook Park pond located approximately 1,400 feet from Pit #1, 1,300 feet from the East Pit, and 500 feet from the Martin Pit; and d. At least six other small ponds (0.1 to 2 acres in size) present since at least the early 1960s, based on their presence on 1966 USGS Quadrangle maps, that are within 1 mile east of the East Pit, Pit #1, and Pit #2. 109. During dewatering, historically, there were no known problems with water supply wells, at least none are documented that can be referenced. Discussion with a local water well driller confirmed, anecdotally, that there is no history of well problems in the Quarry Area. 110. A previous hydrogeologic evaluation of the quarries in the Clear Brook area by Science Applications International Corporation (SAIC), cited by Harlow et al., estimated a reliable yield of 2.17 MGPD and identified "no adverse effects from the withdrawal on the aquifer or other ground-water users in the area.”7 111. The bedrock type, elevation, structure, and dewatering rate estimated by SAIC are similar to the Existing Quarry with no adverse effects identified. 112. Harlow et al. reported that a groundwater flow model prepared by Burbey (2003) indicated that groundwater drawdowns associated with quarry dewatering occurs primarily “in the immediate vicinity of the quarries, and are asymmetric, extending southward and slightly northward (along the strike of the geologic units) however, little water-level decline extends west of the quarries and may indicate a hydrologic boundary or decreased permeability in this direction.”8 The Stephens City quarries are also in the New Market Limestone in a similar structural condition with steep dips and faulting as the Existing Quarry and Proposed Quarry. 113. The favorable geology that minimizes the groundwater drawdowns west and east of the Quarry Area is evidenced by the flowing springs and streams, ponds, and productive water supply wells located east and west of the quarries. 7 Harlow, Jr., George E., Orndorff, Randall C., Nelms, David L., Weary, David J. and Moberg Roger M., 2005, Hydrogeology and Ground-Water Availability in the Carbonate Aquifer System of Frederick County, Virginia, Scientific Investigations Report 2005-5161. 8 Ibid. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 14 Proactive by Design 114. Groundwater level data provided by Carmeuse for wells installed near the Existing Quarry show little impact of quarry dewatering on the groundwater elevations. A residential well located about 300 feet west of the Martin Pit shows water levels 150 feet higher than the quarry floor, indicating very little drawdown in the aquifer and a very limited cone of depression to the west. 115. Similarly, groundwater level data from a monitoring well installed about 600 feet north of the East Pit shows groundwater to be at least 140 feet higher than in the East Pit water level as of September 2023, indicating very little drawdown in the aquifer and a very limited cone of depression to the north. 116. In the Proposed Quarry area, the same geologic setting will minimize groundwater drawdown impact to Turkey Run, Coyle Run, Duncan Run, the nearby springs and ponds, and nearby water supply wells. 117. Recent public discussions about quarry expansion resulted in several public and a couple of private comments about water supply well and surface water quantity and quality concerns that citizens have attributed to the Existing Quarry. As an apparent recent phenomenon, these comments do not seem to represent a history of problems with operations of area quarries as anecdotally stated by the local water well driller based on his experience in the area. Each comment is addressed later in this Report. PROPOSED QUARRY DEWATERING 118. The lack of documented impacts of dewatering of at least six quarries since at least the early 1960s on nearby springs, streams, ponds, and water supply wells provides the most reliable predictions for expectations of potential impacts from the Proposed Quarry. 119. The Proposed Quarry will extract from the same bedrock unit as the other six quarries and, specifically, from the same geologic position relative to a major fault as Pit #3, mined to elevation 500 feet and planned to be mined to elevation 380 feet, and the Martin Pit, planned to be mined to elevation 320 feet. 120. Pit #1, Pit #2, and the East Pit were mined from the opposite downward side of the fault, resulting in the formation being deeper, at a lower elevation. The East Pit was mined to a bottom elevation of 160 feet. 121. Because of the geologic position relative to the fault, the bottom elevation of the Proposed Quarry will be similar to that of the Martin Pit and extend to elevation 300 feet, 140 feet higher elevation than the dewatering that occurred for many years in the East Pit. 122. Although dewatering is ongoing at the Martin Pit, the East Pit has filled with water from the base elevation of 160 feet, to elevation 390 feet as of September 7, 2023. 123. The much higher Proposed Quarry bottom elevation means there will be an even lower potential for impact to nearby surface water or groundwater resources compared to the area of the much deeper East Pit where there has been no demonstrated negative impact. AREA POTABLE WATER SUPPLY WELLS 124. GZA identified 54 possible potable water supply wells based on the presence of residential and commercial buildings observed on aerial photographs ¼- to 1 mile east of the East Pit and nine possible wells west of the East Pit. 125. The areas north, south, and west of the East Pit are within the Frederick Water distribution and are assumed to be connected to the Frederick Water distribution or at least have the option to connect. 126. The nine possible wells located west of the Existing Quarry are presumed to be installed in limestone and the 54 possible well locations identified east of the Existing Quarry are presumed to be installed in the shale/Martinsburg Formation. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 15 Proactive by Design 127. During the history of Existing Quarry operations, complaints about water supply wells were made only recently (May to August 2023) and are discussed in the section below. 128. GZA identified 72 possible potable water supply wells based the presence of residential and commercial buildings observed on aerial photographs within 1 mile of the Proposed Quarry. 129. The areas north, south, and partially west of the Proposed Quarry are within the Frederick Water or Berkely County, West Virginia distribution and are assumed to be connected to the Frederick Water distribution or at least have the option to connect. 130. Of the 72 well locations identified, 15 are believed to be installed in the limestone ¾- to 1 mile west of the Proposed Quarry and 57 are believed to be installed in the shale primarily ½- to 1 mile east of the Proposed Quarry; three of the 57 are located ¼- to 1 miles northeast of the Proposed Quarry. 131. Three of the four recent complaints of grit, sediment, or film on toilet water were from residents located about 1¼ miles southeast of the Proposed Quarry and more than 1½ to 1¾ miles from the Existing Quarry. 132. More than 80% of the presumed shale wells referenced above east of the Proposed Quarry are also located within 1 mile of the Frederick Water Anderson water treatment plant property where they are pumping 2 MGPD from Pit #2 and wells and 1.5 MGPD from wells (OW-1-31E at 0.5 MGPD and Whetzel Well 1 MGPD) into Pit #2. REVIEW OF RECENT SURFACE WATER AND WATER SUPPLY WELL COMPLAINTS GZA reviewed two surface water and seven water supply well complaints received by Carmeuse in 2023, since the public meeting to discuss the Proposed Quarry. If there were additional historical water -related complaints, the current Carmeuse management is not aware of them. The surface water complaints, each paraphrased from public testimony, pertained to the following: • Winchester (City) resident alleged that Carmeuse’s operations have ruined the Redbud Run that comes out of the limestone and by removing the limestone they are removing the water’s natural filtration into that creek. • Jeremiah Lane resident alleged that there was no water in a pond, no streams anymore, no natural spring. Redbud Run 1. Redbud Run is located approximately 3 miles southwest of the southern extent of the East Pit and Martin Pit and flows through/adjacent to two industrial parks. 2. In addition to Hot Run located 300 feet from the Martin Pit and East Pit, Hiatt Run, Lick Run , and several smaller associated tributaries are located between the Existing Quarry and Redbud Run. 3. Groundwater in the vicinity of the Existing Quarry does not discharge to Redbud Run, but flows to the east. 4. This complaint was also filed with Virginia Energy and according to their report on September 7, 2023, “The complainant felt her worries were somewhat exaggerated and would like to withdraw this complaint.” 5. Virginia Energy concluded, “The complainant is approximately 3.9 miles from the mine permit. It is unlikely that mining activity affects Redbud Run or any other streams or ponds in that area.” 6. As documented above, the historical and Existing Quarry have not affected the local springs, streams, and ponds as close as 300 feet from the Quarry Areas; therefore, Redbud Run would not be affected. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 16 Proactive by Design Jeremiah Lane 1. The pond in question is located approximately 1 mile north of the Martin Pit and East Pit. 2. The pond was apparently excavated in 2006-2007, over approximately 2.8 acres. Aerial photographs indicate that in August 2007, the pond was dry. 3. In October 2010, ponded water was evident in the east and west ends of the excavation. 4. Aerial photographs between 2010 and 2023, show wet and dry periods with the ponded water on the western areas not always present. 5. A 2019 aerial photograph on the Frederick County Planning Access Terminal shows the entire 2.8-acre pond area to be flooded. 6. The pond was excavated in an area mapped with upland Oaklet Series soil, at least 90 inches (7.5 feet) of firm clay. 7. The area excavated was apparently a broad topographic swale, but was not mapped by the USGS as a stream or spring. 8. The nearest mapped streams are Clearbrook Run about ½-mile south and Turkey Run about ½-mile north. 9. Based on mapped soil type and topographic position, the pond was excavated in an area that could capture and hold surface water drainage from uplands located primarily to the west, but the pond does not appear to be groundwater fed and could not be impacted by quarry dewatering. 10. There is no hydraulic connection between the alleged dry pond, stream, and spring and the Existing Quarry. The water supply well complaints, each paraphrased from contact with Carmeuse or public testimony, pertained to the following: • A 14-foot-deep, pre-Civil War, hand-dug well within ¼-mile of the Martin Pit; • A dry well greater than ½-mile east of the East Pit; and • Grit in a well within ½-mile east of the East Pit; • Three complaints of grit, sediment, or film on toilet water greater than 1 mile southeast (1) and 1½ to 1¾ miles northeast (2) of the East Pit. • Always has bad water quality in well. Hand-Dug Well 1. It is an unusual circumstance to have an operating well of that age and construction. 2. Although the well has obviously been through similar conditions as the current moderate to severe drought, its recently reported dry condition may be due to the drought. 3. The recent and historic use of the well is not known; i.e., daily, occasional, etc. 4. The well was apparently not affected by several decades of dewatering in the East Pit approximately 1,000 feet east, but may have been affected by recent dewatering in the Martin Pit, located a similar distance to the north, due to the anisotropy associated with the bedrock structure in the region, as described above, which indicates groundwater drawdowns will occur primarily north and south of the quarries. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 17 Proactive by Design Dry Well 1. The well is located more than ½-mile (about 2,800 feet) east of the East Pit. 2. The owner said the well was 135 feet deep. No well log or written records were provided. The well was present in 1975, when the owner bought the property, so it was at least 48 years old. 3. The owner stated that they felt a quarry blast in October 2019, and that sediment increased in their well after that date. 4. The owner stated that the well was muddy on June 9, 2021 and on June 15, 2021. A water well driller verified that the well was dry in June 2021, and a new well was drilled to 300 feet that produced water that flowed naturally under artesian conditions to above the surface on the property, confirming that groundwater levels remained high (above grade) and have not been adversely affected by quarry dewatering. 5. Based on review of aerial photographs, there are approximately 30 water supply wells located closer to the East Pit than this “dry” well. 6. The ground surface at the well location is about elevation 560 feet. 7. Clearbrook Run is located about 150 feet from the well at approximate elevation 550 feet , indicating that groundwater elevations remain high in the area of the well as also confirmed by the above-grade water level in the replacement well. 8. Clearbrook Run is mapped as perennial in the area of the dry well and should contain water at an elevation indicative of the groundwater table surface. 9. The well may have failed for a variety of reasons and it is difficult or impossible to opine on the cause without having been able to examine the well. 10. The location of the well relative to a consistent and reliable stream, the presence of at least 30 wells in the same general bedrock closer to the Existing Quarry, and the above-grade water level in the replacement well suggest that quarry dewatering is not the cause. Wells with Grit, Sediment, Film on Toilet 1. The nature and extent of the grit, sediment, and film on toilet is not known, as these were comments raised at a recent public meeting. 2. Grit and sediment are frequently observed in wells installed in fine-grained, soft, easily erodible bedrock such as shale and such a condition is not necessarily an attribute caused by local bedrock quarrying. 3. The nature of the grit, sediment, and film and well construction and water system would need to be reviewed to opine on the causes of the reported observations. 4. The location of most of these complaints, 1½ to 1¾ miles from the Existing Quarry and the presence of more than 50 wells without these reported issues in the same general bedrock closer to the Existing Quarry suggests that quarrying activities are not the likely cause. Bad Water Quality 1. This well is located about 1¾ miles from the East Pit. 2. Bad water quality is a subjective term and usually indicates the presence of dissolved metals, the odiferous sulfur compounds, and/or total dissolved solids in water from the well. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 18 Proactive by Design 3. Hinkle and Sterrett reported that the water quality in the shale contains higher than average iron and manganese concentrations greater than state and federal drinking water standards. The elevated dissolved iron and manganese concentrations in water from wells in the Martinsburg Formation indicate groundwater with naturally low oxidation- reduction potential, a common occurrence in shale, which results in naturally poor tasting water, water that stains porcelain and appliances, and commonly contains sulfur odor. 4. A local well driller told GZA that the water from the shale commonly contains high iron, sulfur, and other minerals. 5. The water quality at the well in question is likely a naturally occurring condition in the shale aquifer and likely not attributable to operations of the Existing Quarry. A water well complaint was also filed with Virginia Energy on July 24, 2023. According to the Virginia Energy report, “The complainant said that their residence is approximately 2½ miles from the Carmeuse operation. They have noted that the well (about 150 feet deep) has more sediments in the water since around 2015. There is also a smell to the water. A nearby spring dried up in 2022. Has concerns with dust and noise also.” Based on Virginia Energy observations, understanding of groundwater dewatering and distance to the complainant’s well, Virginia Energy concluded on September 9, 2023 that “[n]o enforcement action will be taken at this time.” RECOMMENDED GROUNDWATER LEVEL MONITORING NETWORK GZA reviewed Carmeuse’s Rezoning Proffer Statement submitted July 2023, and in particular Section 8 “Ground Water” which offers repairs to damage caused by mining to water supply wells on Surrounding Property, defined to be within 1,500 feet of the Proposed Quarry property. Based on the size of the Proposed Quarry property, the well protection will extend up to 2,500 feet west, up to 5,000 feet east, up to 3,500 feet north and up to 5,500 feet south of the Proposed Quarry property. Based on our understanding of the hydrogeologic model as described in this Report, Carmeuse’s commitment to the County and the surrounding community is greater than the potential impact and industry standard of care for this geologic setting and the proposed scale of operation. To help predict and avoid unnecessary interruption in use of potable water supply wells and gather data on local surface water resources, we recommended additional surface water and groundwater monitoring locations for consideration as summarized below for the Existing Quarry and Proposed Quarry areas. Existing Quarry During the period of mining and dewatering in the Martin Pit: 1. Continue monitoring water levels in the residential water supply well at 3144 Martinsburg Pike west of the Martin Pit and in monitoring well WI-UG-22-01 on the north side of the East Pit. 2. Continue to monitor the water level recovery and water level in the East Pit until water is either pumped into it from another source or water is pumped out of it. 3. Consider monitoring water levels in an additional residential water supply well west of the Martin Pit along Waverly Road if permission can be obtained. 4. Consider monitoring water levels in an additional residential water supply well east of the East Pit along Walters Mill Lane or Gun Club Road, Highway 666, if permission can be obtained. 5. Consider monitoring surface water levels in the Clearbrook Park Pond if permission can be obtained. 6. Consider monitoring surface water levels in the Hot Run pond southwest of the Martin Pit if permission can be obtained. September 25, 2023 File No. 20.0158489.00 Site Conceptual Hydrogeologic Model Page | 19 Proactive by Design Proposed Quarry Prior to and during the period of mining and dewatering in Pit #3 and the Proposed Quarry: 1. Continue monitoring water levels in monitoring well WI-LGT-21-09, WI-LGT-21-11, and WI-GUM-20-03. 2. Consider installation of an additional well for monitoring water levels in the limestone in the western margins of the Proposed Quarry property north of Branson Spring Road. 3. Consider monitoring water levels in one or two residential water supply wells west of the Proposed Quarry along Thistle Lane, Joline Drive, or F23 if permission can be obtained. 4. Consider monitoring water levels in the Carmeuse-owned residential water supply well northeast of the Proposed Quarry along Woodside Road. 5. Consider monitoring water levels in a residential water supply well east of the Proposed Quarry along Grace Church Road if permission can be obtained. 6. Consider monitoring surface water levels in the Branson Spring pond if permission can be obtained. J:\158400to158499\158489 Carmeuse Winchester\Report\FINAL 20.0158489.00 Prelim Conceptual Hydro Model_Winchester VA 9-25-23.docx Proactive by Design FIGURES Fig ure 1 Quarry Loc ations Legend Frederic k Water Supply W ell Quarry 1 mi N➤➤N Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Fig ure 2 - Regional Top og rap h y 10 mi N➤➤N Image Lands at / Copernicus Image Lands at / Coper nic us Image Lands at / Coper nic us Fig ure 3 - L ocal Surface Water Featu res Legend Spring Pond Stream 2 mi N➤➤N Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Image © 2023 A irbus Image © 2023 A irbus Image © 2023 A irbus Fig ure 4 - Wells Near East Pit Legend 1/4,1/2, 3/4 and 1-Mile Radius of the East Pit Frederic k Water Servic e Area Lim estone (W es t)-Shale (Eas t) Contac t Res idenc e or Comm erical Building W ith Pos sible Water Supply W ell 1 mi N➤➤N Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Fig ure 5 - Wells Near Propo sed Quarry Legend 1/4,1/2, 3/4 and 1-Mile Radius of the Propos ed Quarry Frederic k Water Berkely County Water Servic e Area Lim estone (W es t)-Shale (Eas t) Contac t Res idenc e or Comm erical Building W ith Pos sible Water Supply W ell 1 mi N➤➤N Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus Image © 2023 CNES / A irbus           active by Design                        ATTACHMENT 1    Limitations                 active by Design    HYDROGEOLOGICAL LIMITATIONS  USE OF REPORT   GZA GeoEnvironmental, Inc. (GZA) prepared this Report on behalf of, and for the exclusive use of our Client for the  stated purpose(s) and location(s) identified in the Proposal for Services and/or Report.  Use of this Report, in whole or  in part, at other locations, or  for other purposes, may lead to inappropriate conclusions; and we do not accept any  responsibility for the consequences of such use(s).  Further, reliance by any party not expressly identified in the  agreement, for any use, without our prior written permission, shall be at that party’s sole risk, and without any liability  to GZA.  STANDARD OF CARE   GZA’s findings and conclusions are based on the work conducted as part of the Scope of Services set forth in the  Proposal for Services and/or Report and reflect our professional judgment.  These findings and conclusions must be  considered not as scientific or engineering certainties, but rather as our professional opinions concerning the limited  data gathered during the course of our work. Conditions other than described in this Report may be found at the subject  location(s).   GZA’s services were performed using the degree of skill and care ordinarily exercised by qualified professionals  performing the same type of services, at the same time, under similar conditions, at the same or a similar property.  No  warranty, expressed or implied, is made.  Specifically, GZA does not and cannot represent that the Site contains no  hazardous material, oil, or other latent condition beyond that observed by GZA during its  study.  Additionally, GZA  makes no warranty that any response action or recommended action will achieve all of its objectives or that the findings  of this study will be upheld by a local, state, or federal agency.   In conducting our work, GZA relied upon certain information made available by public agencies, Client and/or others.   GZA did not attempt to independently verify the accuracy or completeness of that information.  Inconsistencies in this  information which we have noted, if any, are discussed in the Report.  SUBSURFACE CONDITIONS   The generalized soil profile(s) provided in our Report are based on widely‐spaced subsurface explorations and are  intended only to convey trends in subsurface conditions.  The boundaries between strata are approximate and idealized  and were based on our assessment of subsurface conditions.  The composition of strata, and the transitions between  strata, may be more variable and more complex than indicated.  For more specific information on soil conditions at a  specific location refer to the exploration logs.  The nature and extent of variations between these explorations may not  become evident until further exploration or construction.  If variations or other latent conditions then become evident,  it will be necessary to reevaluate the conclusions and recommendations of this Report.   Water level readings have been made, as described in this Report, in and monitoring wells at the specified times and  under the stated conditions.  These data have been reviewed and interpretations have been made in this Report.   Fluctuations in the level of the groundwater however occur due to temporal or spatial variations in areal recharge rates,  soil heterogeneities, the presence of subsurface utilities, and/or natural or artificially induced perturbations.  The  observed water table may be other than indicated in the Report.  COMPLIANCE WITH CODES AND REGULATIONS   We used reasonable care in identifying and interpreting applicable codes and regulations necessary to execute our  scope of work. These codes and regulations are subject to various, and possibly contradictory, interpretations.   Interpretations and compliance with codes and regulations by other parties is beyond our control.            active by Design    INTERPRETATION OF DATA   Our opinions are based on available information as described in the Report, and on our professional judgment.   Additional observations made over time, and/or space, may not support the opinions provided in the Report.  CONCEPTUAL SITE MODEL   Our opinions were developed, in part, based upon a comparison of site data to conditions anticipated within our  Conceptual Site Model (CSM).  The CSM is based on available information, and professional judgment.  There are rarely  sufficient data to develop a unique CSM.  Therefore, observations over time, and/or space, may vary from those  depicted in the CSM provided in this Report. In addition, the CSM should be evaluated and refined (as appropriate)  whenever significant new information and/or data is obtained.  ADDITIONAL INFORMATION   In the event that the Client or others authorized to use this Report obtain additional information on environmental or  hazardous waste issues at the Site not contained in this Report, such information shall be brought to GZA's attention  forthwith.  GZA will evaluate such information and, on the basis of this evaluation, may modify the conclusions stated  in this Report.  ADDITIONAL SERVICES   GZA recommends that we be retained to provide services during any future investigations, design, implementation  activities, construction, and/or property development/ redevelopment at the Site.  This will allow us the opportunity  to: i) observe conditions and compliance with our design concepts and opinions; ii) allow for changes in the event that  conditions are other than anticipated; iii) provide modifications to our design; and iv) assess the consequences of  changes in technologies and/or regulations.                 active by Design                        ATTACHMENT 2    Geologic Map – Inwood Quadrangle                 active by Design                        ATTACHMENT 3    Geologic Map – Stephenson Quadrangle               active by Design                        ATTACHMENT 4    Schematic of Conceptual Groundwater Flow in Fractured Carbonate Bedrock                 active by Design                        ATTACHMENT 5    Sinkhole Figures       U.S. DEPARTMENT OF THE INTERIOR MISCELLANEOUS FIELD STUDIES U.S. GEOLOGICAL SURVEY MAP MF-2262 78°30' 39°15' DESCRIPTION OF LITHOLOGIC UNITS 78°15' 39°30' 6 Interbedded shale, siltstone, and sandstone of the Middle and Upper Ordovician Martinsburg Formation 5 High calcium limestone of the Middle Ordovician New Market Limestone, limestone and chert of the Middle Ordovician Lincolnshire Limestone, and interbedded limestone, shaly limestone, and calcareous shale of the Middle Ordovician Edinburg and Oranda Formations 4 Interbedded limestone and dolostone of the Lower and Middle Ordovician Rockdale Run Formation and dolostone and minor limestone of the Middle Ordovician Pinesburg Station Dolomite 3 siliceous-laminated limestone of the Lower Ordovician Stonehenge Limestone 2 Interbedded dolostone, limestone, and dolomitic shale of the Middle and Upper Cambrian Elhrook Dolomite and interbedded limestone, dolostone, and calcareous sandstone of the Upper Cambrian and lowest Ordovician Conococheague Formation 1 Interbedded dolostone and limestone of the Lower Cambrian Tomstown Dolomite and interbedded limestone, dolostone, siltstone, sandstone, and shale of the Lower and Middle Cambrian Waynesboro Formation EXPLANATION OF MAP SYMBOLS Sinkhole--COL - collapse sinkhole S. Spring--Includes ephemeral and perennial • Cave entrance Travertine or marl deposit Geologic contact -v—v- Thrust fault--Sawteeth on upper plate Strike-slip fault--Arrows show direction of relative movement Oakland „IT A 6 r 39°00' Hook M Lorna r a Sp 55) r ; - 2..?Spririg / t• li , / Uc 7 o Gravel r o • hen O • F Mo -ails Rock Sp'. Nllex • ouafain- alk ' 0 -"Pe." La Run 30 Oar a Leb.a. Church, Chpo Road' yob t ige pain iew andr Mt Williams ..5tg Sty lrr da Marlboro 200 Hayfi d 4010' satat • ittwr. . • le ills • a ‘K ryAL ip• '-`•.‘3 CC ve- O 1 q) Round Hill "53•,. Opequon 2 4 II lines o / oao Slice Lake I Albin Radio Towers Barton Hill Cres P 00 22 r -fir 44 kee Hill 0 Green Sprit). Ce‘ar) Gran Ct 0 4y • L o 37 anotown S S irc /./E unnysid ort oy, ios 4 I White Hall C layp -s 4/ S 0 Si) Grimes — Grimes fa Win ,P r Mu I Airp • P. kins v (ex Am"`1\, 0 rearm' Gott Ones 59pring ills Gap /e\ O • P • 4111 can t- c43 r 1)•, w r .4( nion Corner e a I ow Tor 00 Aitotial Rest si ok Burn 6 Factory o firol:17 Lost co er rjf>: 1) Oa 0, • Sugar fli11 one Bridge Milldal ler Bun eFecri Spring Run Legtown 78°30' Base from U.S. Geological Survey, 1983 15' SCALE 1:100 000 1 CENTIMETER ON THE MAP REPRESENTS 1 KILOMETER ON THE GROUND CONTOUR INTERVAL 20 METERS KILOMETERS 1 0 1 2 3 4 5 6 1 8 9 10 H I I 1—I MILES 1 0 2 3 4 5 6 • cetown fr Bosoc ar. ndy Exper miry of V ( Specks 4 • Millwood rtn Trea Evans Tablers Station c 78°00' 39°30' Three 51) -4•4? 441 Hei 1.0 Swimle • • • " 4 :255) Claytunville Sf-114NAIV Carter • • . : Bethel . 817uncif flO 1 5' INTRODUCTION Rocks of the Shenandoah Valley within the Winchester 30' X 60' quadrangle are dominantly limestone and dolostone which have moderate karst development. Recent urbanization in the northern part of the Shenandoah Valley has increased the potential for formation of sinkholes and contamination of ground water. This map, at a scale of 1:100,000, shows areas of sinkholes and the generalized bedrock geology. It is useful for determining areas of potential future sinkhole development and areas that are generally susceptible to ground-water contamination. Features plotted include sinkholes, caves, springs, and travertine deposits. The sinkholes were identified from U.S. Geological Survey (USGS) 7.5-minute topographic quadrangle maps; some were mapped in the field, and others were derived from the mapping of Hubbard (1983), Holmes and others (1984), Holmes and Wagner (1987), and Heidel and others (1991). Sinkholes in Clarke County, Virginia, were compiled from Hubbard (1990). Since various sources were used to compile the sinkholes on the map, coverage in some counties is better than others. For instance, Hubbard (1990) performed an in-depth photointerpretation for Clarke County, Virginia, resulting in a greater number of sinkholes for this county compared to the other counties in which sinkholes were compiled from topographic maps and soil surveys. The purpose of the present map is to show all of the reported sinkholes for the map area. Hubbard (1991) reported that only 19 percent of the sinkholes identified by photointerpretation are indicated on topographic maps by closed contours and 3 percent of the sinkholes shown in soil surveys are found on topographic maps for Clarke County. Springs were plotted from USGS 7.5-minute topographic quadrangle maps and from Price and others (1936), and McColloch (1986) for West Virginia and from Wright (1990) for Virginia. Travertine and marl deposits located on the Winchester 30' X 60' quadrangle were compiled from fi eld mapping and from Giannini (1990) and Sweet and Hubbard (1990). GEOLOGIC SETTING The Shenandoah Valley was defined by Hack (1965) as "an elongate area about 140 miles long that drains into the Potomac River" and "lies between the Blue Ridge Mountains on the southeast and the North and Shenandoah Mountains on the northwest." Rocks of the Shenandoah Valley in the Winchester 30' X 60' quadrangle range from Early Cambrian to Middle Ordovician in age. The carbonate rocks are divided into an eastern and western belt separated by shale and some sandstone of the Middle and Upper Ordovician Martinsburg Formation (unit 6 on map) which defines the axis of a large regional downfold, the Massanutten synclinorium. Rocks on the east limb of the synclinorium include carbonate rocks from the Lower Cambrian Tomstown Dolomite through the Middle Ordovician Edinburg and Oranda Formations. The west limb includes rocks from the Upper Cambrian Elbrook Formation through the Middle Ordovician Edinburg and Oranda Formations. The southeast boundary of the map is defined by the contact of the Tomstown with the underlying clastic rocks of the Blue Ridge province. The northwest boundary is the North Mountain fault zone which places Cambrian and Ordovician carbonate rocks over Upper Ordovician through Devonian clastic rocks. The generalized geology shown on this map was modified from Butts and Edmundson (1966), Edmundson and Nunan (1973), Cardwell and others (1968), McDowell (1991), and Orndorff and others (1993). The lithostratigraphic units, or formations, are combined into units characterized by their dominant rock types. For instance, interbedded limestone and dolostone of the Elbrook Formation and Conococheague Limestone are combined into one lithologic unit (unit 2), whereas the predominantly limestone lithology of the Stonehenge Limestone is considered its own lithologic unit (unit 3). Combined in this manner, the lithologic control on the development of karstic features may be examined. The rocks of the Shenandoah Valley are folded and faulted, and contain numerous joints, and veins. Folds are northeast trending and are generally overturned in the eastern belt and upright in the western belt. Faults are mainly thrust faults or high angle reverse faults, however, several cross faults also occur. KARST FEATURES Karst development in the study area is expressed by sinkholes, caves, and areas of poorly developed surface drainage on carbonate rocks. The most common karst features in this part of the Shenandoah Valley are sinkholes of various sizes. These closed depressions result from subsidence due to solution of the bedrock or collapse of roof rocks into subsurface solution cavities in carbonate rocks. Hack (1965) concluded that sinkholes in the southern part of the Shenandoah Valley were controlled by character of the bedrock, thickness of the overlying residuum, geologic structure, and their relationship to streams. The results of this study show that the lithologic characteristics, fracture density of the bedrock, and the proximity of carbonate rocks to streams are the main controlling factors in sinkhole formation. Sinkholes are more abundant and increase in size near intrenched streams. This relationship occurs along Cedar Creek northwest of Middletown along the Frederick and Shenandoah County line, Virginia, and along the Shenandoah River in Clarke County, Virginia. There, in the southeast corner of the map, lithologic unit 1 (Tomstown Dolomite and Waynesboro Formation) has a relatively high concentration of sinkholes compared to the other units (table 1). In the northern Valley and Ridge province "of Virginia, Hubbard (1983) attributed the greater development of sinkholes near streams to the steepened hydraulic gradient and increased rate of ground -water flow in these areas. Enhanced sinkhole development near streams in the Winchester quadrangle can also be attributed to this cause. Many of the springs in the Shenandoah Valley of the Winchester 30' X 60' quadrangle are structurally controlled, occurring where fault planes intersect the surface. Examples of these fault controlled springs are Shawnee Spring in Winchester, Frederick County, Virginia and Horsepen Spring in Clarke County, Virginia. Travertine deposits are associated with springs and in areas where stream waters supersaturated with respect to calcite traverse rough stream beds. A combination of increased temperature and aeration as surface streams flow over rough beds causes degassing of carbon dioxide (pCO2) and loss of calcite supersaturation, resulting in deposition of calcite (White, 1988). A spectacular travertine deposit is located on the northeast bank of Cedar Creek where Fawcett Run joins the creek just upstream from the State Route 628 bridge, 0.5 mi south of Marlboro, Frederick County, Virginia. This deposit has formed downstream from an unnamed spring at Marlboro and where Fawcett Run drops approximately 15 ft at a waterfall into Cedar Creek. The marl deposits located just north of Winchester, Frederick County along Redbud Run and those in Clarke County, Virginia have been mined for agricultural lime (Sweet and Hubbard, 1990). ENVIRONMENTAL IMPLICATIONS AND PROBLEMS RELATED TO KARST Problems associated with karst in the Shenandoah Valley are subsidence, collapse, and ground -water contamination. Jennings (1985) defines subsidence as "the mass movement of soils, weathering mantles, and superficial deposits that is often gradual," whereas collapse is defined as "geologically sudden mass movement of the karst bedrock." Collapse sinkholes are generally rare in the Shenandoah Valley. However, both natural processes and man's influence do provide a risk; for example, Newton and Tanner (1987) provide several case histories of human-induced sinkholes in the eastern United States. In November of 1992, a collapse sinkhole developed in northern Clarke County, Virginia which caused extensive property damage completely engulfing a home in less than two months. A common cause of collapse is a drop in the water table due to extended droughts or excessive pumping of the ground water (Newton and Tanner, 1987). In the study area, subsidence typically occurs over a long period of time by solutional enlargement of fractures such as joints, faults, and bedding planes. 1 - Reconnaissance geologic mapping by Orndorff, modified from Cardwell and others (1968) 2 - Reconnaissance geologic mapping by Orndorff, 39°00' modified from Butts and Edmundson (1966) 78°00' Manuscript approved for publication January 25, 1994 INTERIOR —GEOLOGICAL SURVEY, RESTON, VA -1994 SINKHOLES AND KARST-RELATED FEATURES OF THE SHENANDOAH VALLEY IN THE WINCHESTER 30' x 60' QUADRANGLE, VIRGINIA AND WEST VIRGINIA By Randall C. Orndorff and Keith E. Goggin 1994 co.oGicAL tt.43. itss -c ON. SEP 1 2 1994 3 - Reconnaissance geologic mapping by Orndorff, modified from Edmundson and Nunan (1973) 4 - Geologic mapping by McDowell, unpub. data 5 - Geologic mapping by Orndorff and others (1993) 6 - Reconnaissance geologic mapping by Orndorff, unpub. data 5 4 2 6 1 3 SOURCES OF GEOLOGIC DATA A more serious problem with karst in the Shenandoah Valley is ground -water contamination (Hubbard, 1990). Ground -water movement in the carbonate rocks of the Shenandoah Valley is extremely complicated. The openings in these rocks, consisting of joints, faults, and bedding planes, may be enlarged by solution of the limestone and dolostone resulting in a complex drainage pattern. This may increase the potential for ground -water contamination and complicates prediction of areas that may become affected. Dye-tracer tests, where fluorescent dye is introduced into a sinkpoint and detected at springs, wells, or surface streams, have been conducted to gain a better understanding of the Shenandoah Valley ground -water system (Kozar and others, 1991; Jones, 1991). Jones (1991), for example, reported travel times of three to five months for distances of one to three miles, which suggests that karstic fl ow is well developed in certain areas. Sources of ground -water contamination in the Shenandoah Valley of the Winchester quadrangle include agricultural runoff (pesticides, herbicides, animal waste), industrial pollution, underground storage tanks, regional landfills, and private septic systems. Areas affected by contaminants from these sources are difficult to predict due to the complex hydrogeologic setting in the karst terrain. During the last 200 years sinkholes have been used for dumping of waste and therefore are direct sources for ground -water contaminants. Slifer and Erchul (1989) estimate that there are over 4,600 illegal dumps in the karst area of the Valley and Ridge Province in Virginia, 30 percent of which are likely sinkhole dumps. Also, the possibility of buried sinkholes beneath the regolith which have no surface expression and the pinnacled nature of the carbonate bedrock should be considered in landfill and other land -use studies. Significant portions of the study area are underlain by carbonate rocks, but exhibit no surface expression of subsidence features. However, here too, karst processes are active. In these areas, karstification is expressed by poorly developed surface drainage, as well as some minor solutional sculpting of the exposed bedrock (karren features). Areas such as these present a variety of potential problems for land users, including relatively rapid movement of contaminated ground water, and difficulties in engineering building foundations due to differential compaction, soil piping, and collapse of subsurface cavities (White, 1988). CONCLUSIONS The existence of sinkholes, caves, pinnacled bedrock, and other karst features in the Shenandoah Valley of the Winchester 30' X 60' quadrangle indicate potential environmental and engineering hazards associated with urban development. Ground- water contamination is a serious concern and the complex hydrogeologic systems associated with karst create difficulties in predicting the rate and direction of ground- water movement. Also, ground-water contamination can affect surface water quality where it rises at springs. With the increase in industrial development combined with the long agricultural history of this part of the Shenandoah Valley, the potential of ground- water contamination has also increased. Subsidence and collapse, although rare, have occurred in the recent past and need to be considered in land use planning and construction. These problems associated with karst terrains should be considered at all scales of development as land use planning. REFERENCES CITED Butts, Charles, and Edmundson, R.S., 1966, Geology and mineral resources of Frederick County: Virginia Division of Mineral Resources Bulletin 80, 142 p. Cardwell, D.H., Erwin, R.B., and Woodward, H.P., 1968, Geologic map of West Virginia: West Virginia Geological and Economic Survey, scale 1:250,000. Edmundson, R.S., and Nunan, W.E., 1973, Geology of the Berryville, Stephenson, and Boyce quadrangles, Virginia: Virginia Division of Mineral Resources Report of Investigations 34, 112 p. Giannini, W.F., 1990, A commercial marl deposit near Winchester, Virginia, in Herman, J.S., and Hubbard, D.A., Jr., eds., Travertine-marl: stream deposits in Virginia: Virginia Division of Mineral Resources Publication 101, p. 93-99. Hack, J.T., 1965, Geomorphology of the Shenandoah Valley Virginia and West Virginia and origin of the residual ore deposits: U.S. Geological Survey Professional Paper 484, 84 p. Heidel, L.W., Ealy, E.P., and Osborne, Steve, 1991, Soil survey of Shenandoah County, Virginia: Department of Agriculture, Soil Conservation Service, 290 p. Holmes, R.L., and Wagner, D.L., 1987, Soil survey of Frederick County, Virginia: Department of Agriculture, Soil Conservation Service, 206 p. Holmes, R.L., Wagner, D.L., and Racey, D.L., 1984, Soil survey of Warren County, Virginia: Department of Agriculture, Soil Conservation Service, 159 p. Hubbard, D.A., Jr, 1983, Selected karst features of the northern Valley and Ridge province, Virginia: Virginia Division of Mineral Resources Publication 44, scale 1:250,000. 1990, Map of selected hydrologic components for Clarke County, Virginia: Virginia Division of Mineral Resources Publication 102, plate 2, scale 1:50,000. 1991, Regional karst studies: who needs them?, in Kastning, E.H., and Kastning, K.M., eds., Appalachian karst: National Speleological Society, Proceedings of the Appalachian Karst Symposium, March 23-26, 1991, Radford, Virginia, p. 135-138. Jennings, J.N., 1985, Karst geomorphology: New York, Basil Blackwell, 293 p. Jones, W.K., 1991, The carbonate aquifer of the northern Shenandoah Valley of Virginia and West Virginia, in Kastning, E.H., and Kastning, K.M., eds., Appalachian karst: National Speleological Society, Proceedings of the Appalachian Karst Symposium, March 23-26, 1991, Radford, Virginia, p. 217-222. Kozar, M.D., Hobba, W.A., Jr., and Macy, J.A., 1991, Geohydrology, water availability, and water quality of Jefferson County, West Virginia, with emphasis on the carbonate area: U.S. Geological Survey Water-Resources Investigations Report 90-4118, 93 p. McColloch, J.S., 1986, Springs of West Virginia--50th anniversary revised edition: West Virginia Geological and Economic Survey, Volume V-6A, 493 p. McDowell, R.C., 1991, Preliminary geologic map of the Winchester quadrangle: U.S. Geological Survey Open-File Report 91-22, scale 1:100,000. Newton, J.G., and Tanner, J.M., 1987, Case histories of induced sinkholes in the eastern United States, in Beck, B.F., and Wilson, W.L., Karst hydrology: Engineering and environmental applications: Proceedings of the Second Multidisciplinary Conference on Sinkholes and the Environmental Impacts of Karst, Orlando, Florida, February 9-11, 1987, p. 15-23. Orndorff, R.C., Epstein, J.B., and McDowell, R.C., 1993, 'Preliminary geologic map of the Middletown quadrangle, Frederick and Shenandoah Counties, Virginia: U.S. Geological Survey Open-File Report 93-24, scale 1:24,000. Price, P.H., McCue, J.B., and Hoskins, H.A., 1936, Springs of West Virginia: West Virginia Geological Survey, Volume 6, 146 p. Slifer, D.W., and Erchul, R.A., 1989, Sinkhole dumps and the risk to ground water in Virginia's karst areas, in Beck, B.F., Engineering and environmental impacts of sinkholes and karst: Proceedings of the Third Multidisciplinary Conference on Sinkholes and the Engineering and Environmental Impacts of Karst, St. Petersburg Beach, Florida, October 2-4, 1989, p. 207-212. Sweet, P.C., and Hubbard, D.A., Jr., 1990, Economic legacy and distribution of Virginia's Valley and Ridge province travertine-marl deposits, in Herman, J.S., and Hubbard, D.A., Jr., eds., Travertine-marl: stream deposits in Virginia: Virginia Division of Mineral Resources Publication 101, p. 129-138. White, W.B., 1988, Geomorphology and hydrology of karst terrains: Oxford University Press, New York, 464 p. Wright, W.G., 1990, Ground-water hydrology and quality in the Valley and Ridge and Blue Ridge physiographic provinces of Clarke County, Virginia: U.S. Geological Survey Water Resources Investigations Report 90-4134, 61 p. West Virginia Virginia INDEX MAP Winchester 30 X 60 minute quadrangle Study area ) Table 1.--Distributions of sinkholes in relation to lithologic unit in the Shenandoah Valley area of the Winchester 30' X 60' quadrangle Lithologic Area unit (km2 ) Number of sinkholes mapped Number of sinkholes per km' 1 20.4 50 2.54* 2 329.5 109 0.33 3 42.5 13 0.31 4 253.7 415 1.64 5 71.3 92 1.29 *Ratio is high due to proximity of lithologic unit to incised Shenandoah River Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government For sale by U.S. Geological Survey, Map Distribution, Box 25286, Federal Center, Denver, CO 80225           active by Design                        ATTACHMENT 6    Images of Rock Types                    © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google © 2023 Google