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HomeMy WebLinkAbout6403_Nash_HydroPlan_20161024 11112 BRANDING IRON PLACE, WENDELL, NC 27591 919-366-3663 Office ● 919-995-0363 Cell ● nautilusgeocon@gmail.com DESIGN HYDROGEOLOGIC REPORT NASH COUNTY C & D LANDFILL EXPANSION PERMIT # 6403-CDLF-2000 NASHVILLE, NASH COUNTY, NORTH CAROLINA AUGUST 2014 Revised October 2016 Prepared by: Nautilus Geologic Consulting, PLLC License # C-489 Brian S. Boutin, PG Prepared for: Nash County Solid Waste Department P. O. Box 849 Nashville, NC 27856-0849 i Table of Contents Page 1.0 INTRODUCTION.............................................................................................................. 1 2.0 REGIONAL GEOLOGY AND HYDROGEOLOGY .................................................... 2 2.1 Regional Geology .................................................................................................... 2 2.2 Regional Hydrogeology .......................................................................................... 4 3.0 FIELD OBSERVATIONS ................................................................................................. 6 3.1 Topographic Setting and Drainage ....................................................................... 6 3.2 Springs, Streams and Other Groundwater Discharge Features ........................ 6 3.3 Bedrock Characteristics ......................................................................................... 6 4.0 TEST BORINGS AND PIEZOMETERS ........................................................................ 8 5.0 LABORATORY GEOTECHNICAL TESTING ........................................................... 10 6.0 SITE GEOLOGY AND HYDROGEOLOGY ................................................................ 11 6.1 Site Geology ........................................................................................................... 11 6.2 Site Hydrogeology ................................................................................................. 13 6.2.1 Results of Aquifer Tests ........................................................................................ 13 6.2.2 Short and Long Term Groundwater Elevations ................................................. 14 6.2.3 Horizontal and Vertical Groundwater Flow ...................................................... 16 6.2.4 Estimated Seasonal High Water Table ................................................................ 19 6.2.5 Special Geologic Considerations .......................................................................... 19 Figures 1. Site Location Map 2. Site Map 3. Geologic Map (In Text) 4. Geologic Cross Section A-A’ 5. Geologic Cross Section B-B’ 6. Geologic Cross Section C-C’ 7. Water Table Elevation Contour Map: September 2013 8. Seasonal High Water Table Elevation Contour Map Tables 1. Test Boring/Piezometer Data 2. Geotechnical Laboratory Data: Grain Size and Unified Soil Classification 3. Hydrogeologic Properties of Lithologic Units 4. Short-Term Groundwater Level Observations 5. Long-Term Groundwater Level Observations ii 6. Horizontal Groundwater Gradient and Velocity Calculations 7. Vertical Groundwater Gradient Calculations Appendices A. Test Boring Logs and Piezometer Completion Records B. Geotechnical Laboratory Data C. Slug Test Results 1 1.0 INTRODUCTION Nash County proposes to build an approximately 17 acre expansion of their currently permitted 11-acre Construction & Demolition debris landfill (CDLF), located at 3057 Duke Road (S.R. 1411) in Nashville, Nash County, North Carolina (Figure 1). The expansion and future operations at this facility will be conducted in accordance with Solid Waste Rules 15A NCAC 13B .0531 et seq., which became effective January 1, 2007. This CDLF is an “existing” facility as of August 31, 2007, with respect to the 2007 Solid Waste Act, and the facility meets the vertical separation requirements of the Rules; as such the proposed expansion of this facility does not require a synthetic liner; however, the soil-type requirements prescribed by the Rules for the upper two (2) feet beneath the base grade do apply for proposed expansion, as do the final cover requirements. The permitted facility boundary encompasses approximately 84 acres (Figure 2). In 1998, the NC Solid Waste Section (NCSWS) reviewed the Site Application for the Nash County CDLF. The 1998 Site Application, prepared by Camp Dresser and McKee and submitted on behalf of Nash County, studied the suitability of the approximately 84-acre site proposed for development as a CDLF. The 1998 Site Application was reviewed and approved by the NCSWS in a September 17, 1998 letter, subject to terms and conditions outlined in the letter. The Nash County CDLF is currently operating Phase 3 of the currently permitted 11-acre landfill. The proposed 17-acre expansion will be permitted as a substantial amendment in accordance with 15A NCAC 13B .0533 (a) (3) Substantial amendment to the permit. The portion of the landfill property previously studied in the 1998 Site Application is the same portion of the landfill property on which the proposed expansion of the C&D landfill will be located. This volume presents the Design Hydrogeologic Report for the proposed CDLF expansion in accordance with 15A NCAC 13B .0538 (b). The report is focused on the proposed 17-acre expansion and supplements information presented in the Site Hydrogeologic Report submitted as part of the original Site Application in 1998. 2 2.0 REGIONAL GEOLOGY AND HYDROGEOLOGY 2.1 Regional Geology The Nash County CDLF is located within the Eastern Slate Belt of the Piedmont physiographic province. More specifically, the site is located within the Spring Hope terrane, a Neoproterozoic suprastructural volcanic arc complex that, in the vicinity of the site, is bounded to the west by granitoid plutonic rocks of the Castalia Pluton and to the east by the Hollister Fault.1 An excerpt of the 2009 Preliminary Bedrock Geologic Map of the Gold Sand, Centerville, Castalia and Justice 7.5-minute quadrangles on which the Nash County CDLF location is shown is presented below as Figure 3. Figure 3 Excerpt from Stoddard et al. 20092 1 Stoddard, Edward F., 2012; Rocks, structures and geologic relationships of the Spring Hope Terrane, northeastern North Carolina Piedmont; Paper No. 203-5, 2012 Geological Society of America Annual Meeting, Charlotte, North Carolina. 2 pp. 2 Stoddard, E. F., Stephen Fuemmeler, Randy Bechtel, Timothy W. Clark and D. Parker Sprinkle, II, 2009; Preliminary Bedrock Geologic Map of the Gold Sand, Centerville, Castalia and Justice 7.5-minute quadrangles, Franklin, Nash, Warren and Halifax Counties, North Carolina; North Carolina Geological Survey Open File Report 2009-3. 3 Bedrock within the Spring Hope terrane is largely composed of greenschist facies mafic to felsic metavolcanic rocks and volcanogenic metasedimentary rocks.3 The volcanogenic metasedimentary rocks have protoliths of siltstone, sandstone and mudstone, with rare conglomerate, that occur in sequences and are interpreted as being deposited as turbidites and reworked pyroclastic-epiclastic sediments.1 In the area of the site, bedrock is largely composed of metamorphosed siltstone (argillite, phyllite, schist). Widely spaced vertical to steeply dipping Mesozoic diabase dikes are present within the Spring Hope terrane which generally strike northwest-southeast; however, none have been mapped in the area of the Nash County CDLF. In addition, small, isolated intrusive metadiorite and metabasalt sills and dikes occur within the mapping unit where the Nash County CDLF is located. However, none were observed during this or previous investigations. Major lithologic units near the site (Figure 3) include2: CZfmv – felsic metavolcanic rocks; includes distinctive bluish, gray or white weathering, thinly layered and locally strongly fissile fine grain rocks consisting predominantly of very strongly recrystallized mosaic matrix of very fine quartz + sodic plagioclase +/- microcline grains. CZmmv – mafic volcanic rocks; includes massive fine to medium-grained epidote + chlorite + actinolite + albite greenstone, chlorite phyllite and schist; weakly to non- foliated medium to coarse-grained amphibolite consisting of hornblende and intermediate plagioclase, with or without epidote/clinozoisite and Fe-Ti oxide minerals; and metabasalt with relict igneous texture and common quartz +/- epidote amygdules. CZmgs – undivided metasedimentary rocks; predominantly metagraywacke and metasiltstone; also includes minor metamudtone and metaconglomerate. PPga – granitoid facies a; moderately K-feldspar porphyritic, medium to coarse-grained, buff weathering, white or pink and white, unfoliated biotite granite and monzogranite. The Nash County CDLF is located within the CZmgs mapping unit, which is consistent with the few PWR exposures observed at the site as well as the lithology and texture of the saprolite and PWR encountered during drilling. Geologic evidence infers a complex sequence of three or more separate fold events in the eastern Piedmont. South-plunging map-scale folds manifest the most recent folding event, the most 3 Horton, Jr., J. Wright, Avery Ala Drake, Jr. and Douglas W. Rankin, 1994. Terranes and overlap sequences in the Central and Southern Appalachians, an expanded explanation for part of the Circum-Atlantic terrane map. USGS Open File Report 94-682. 43 pp. 4 prominent of which in the Spring Hope terrane is the Spring Hope synform, the axis of which lies immediately west of the Nash County CDLF site. Where bedding planes can be inferred, beds appear to be vertical to sub-vertical in all cases.1 Bedding plane and axial plane foliation is closely spaced, steeply dipping and generally strikes approximately N20W to N20E. Joints are likewise steeply dipping, are widely spaced and generally strike N15E to N35E and N35W to N60W based on measurements made at outcroppings of PWR in the borrow area at the Nash County CDLF. This is consistent with the attitude of joints mapped in the area of the site. 2.2 Regional Hydrogeology The Piedmont Province is generally underlain by a complex, two-part, regolith-fractured crystalline rock aquifer system. The regolith (residuum and saprolite) varies in thickness up to 150 feet and generally consists of an unconsolidated or semi-consolidated mixture of clay and fragmental material ranging in size from silt to boulders formed by the in-situ weathering of the bedrock4. The regolith acts as a groundwater reservoir that slowly recharges the underlying bedrock aquifer by drainage in the Piedmont groundwater system4. Relict structures and directional properties controlling permeability or hydraulic conductivity are generally retained within the saprolite. A highly permeable transition zone occurs at the base of the regolith where saprolite grades into unweathered bedrock. The transition zone is commonly referred to as partially weathered rock (PWR) and is characterized by standard penetration test resistance of greater than 100 blows per foot while still allowing penetration by hollow stem auger drilling. The thickness and texture of the transition zone depends largely on the texture and composition of the parent rock, with more well-defined zones usually associated with highly foliated metamorphic parent rock4. The high permeability of the transition zone is most likely the result of incomplete weathering in the lower regolith such that chemical alteration of the bedrock has not progressed to a stage where clay and other weathering by-products have been formed in sufficient quantities to fill fractures and other secondary openings. Groundwater movement within the fractured bedrock occurs primarily within secondary openings that were formed during deformation and unloading. These secondary openings are primarily joints, faults and/or bedding-plane and axial plane partings that form an interconnected system of channels through which groundwater can flow. Based on the current and previous hydrogeological studies conducted at the site, and past experience with similar sites in the Piedmont region, the area groundwater flow regime appears to follow the general model for Piedmont aquifer systems as described above. The shallow aquifer in the area appears to be associated with relatively short segmented drainage features that 4 Daniel, III, Charles C. and Paul R. Dahlen, 2002. Preliminary hydrogeologic assessment and study plan for a regional ground-water resource investigation of the Blue Ridge and Piedmont provinces of North Carolina. U.S. Geological Survey Water-Resources Investigations Report 02-4105, 60p. 5 developed along regional jointing and/or foliation. Shallow groundwater occurs within the weathered metasiltstone regolith and PWR and serves as a reservoir for recharging the underlying bedrock aquifer. Recharge to the regolith occurs via infiltration of precipitation. Annual precipitation in the Nash County area is approximately 43 inches (State Climate Office of North Carolina), of which approximately 13 inches provides recharge to aquifers. A portion of the groundwater moves through the regolith and into interconnected fractures in the underlying bedrock while another portion flows through the regolith parallel to the bedrock surface. Groundwater discharges as seepage into perennial streams and associated wetlands, lakes or other surface water bodies that occupy broad incised drainages. Evapotranspiration also accounts for a significant portion of groundwater discharge. At the Nash County CDLF site, the major drainage feature is Pig Basket Creek which flows from northwest to southeast to the east of the landfill. The movement of groundwater through the bedrock aquifer and the overlying saprolite aquifer is strongly influenced by topography which generally controls the location of recharge and discharge zones. Groundwater within the Piedmont generally moves from topographically high areas (recharge zones) to topographically low areas within and along stream valleys (discharge areas). The flow of groundwater is also influenced by fracture zones and foliation within the bedrock and which may be retained as relic features within the saprolite and PWR. In the Piedmont, productive fractures generally occur at depths above 300 to 350 feet below the bedrock surface.5 Depending on the degree of fracturing, well yields generally range from less than 1 gallon per minute (gpm) to 60 gpm in the Piedmont. Typically, hydraulic conductivities in the regolith range from 2 x 10-3 feet per minute (ft/min) [1 x 10-3 centimeter per second (cm/s)] to 5 x 10-5 ft/min (3 x 10-5 cm/s). Hydraulic conductivities in the bedrock aquifer typically range from 1 x 10-2 ft/min (5 x 10-3 cm/s) to nonconductive. 5 LeGrand, Sr., Harry E., 2004. A Master Conceptual Model for Hydrogeological Site Characterization in the Piedmont and Mountain Region of North Carolina, A Guidance Manual. North Carolina Department of Environment and Natural Resources, Division of Water Quality, Groundwater Section. 55 pp. 6 3.0 FIELD OBSERVATIONS 3.1 Topographic Setting and Drainage The proposed CDLF expansion encompasses approximately 17 acres and is located more than two miles northwest of the city of Nashville, North Carolina (Figure 1). The proposed CDLF expansion area, along with topographic contours, is depicted in Figure 2. The topography in the area of the site is characterized by uplands having gentle to moderate, rounded slopes separated by broad, incised drainages that are commonly fringed with wetlands, typical of Piedmont terrain. Ground surface elevations within the boundaries of the proposed CDLF expansion area range from approximately 200 feet msl (mean sea level) in the northeast area to approximately 242 feet msl near the southwest corner of the active landfill (Figure 2). Overall, the topography at the site generally slopes to the east and southeast toward Pig Basket Creek, located approximately 350 feet east of the proposed CDLF expansion area, and an unnamed tributary to Pig Basket Creek, located approximately 500 feet southeast of the CDLF expansion area. The upper reach of a drainage swale is located in the southeast corner of the expansion area, and a larger, better defined drainage swale is located approximately 200 to 300 feet south of the southern border of the expansion area. Surface runoff follows the topographic contours and generally drains to the east and southeast from the expansion area. Approximately 50% of the land area within the borders of the proposed CDLF expansion is covered with coniferous forest and the remaining land is open, having undergone extensive reworking as the result of soil borrowing. A relatively steep topographic slope exists along the east margin of the active soil borrow area down to the forested area in the south-central portion of the proposed expansion area. Another relatively steep topographic slope exists along the east margin of the forested area down to the former soil borrow area in the northeast portion of the proposed CDLF expansion. 3.2 Springs, Streams and Other Groundwater Discharge Features No springs, seeps, wetlands, perennial streams or other groundwater discharge features are present within the boundaries of the proposed CDLF expansion area. The closest groundwater discharge features to the expansion area are Pig Basket Creek and associated wetlands to the east and the unnamed tributary to Pig Basket Creek to the south of the proposed expansion area (Figure 2). These surface water bodies are the principal groundwater discharge features in the area of the site. 3.3 Bedrock Characteristics No bedrock outcrops were identified within or near the proposed CDLF expansion area. Moreover, bedrock was not encountered in any of the boreholes drilled at the site during this or 7 previous investigations. The deepest borehole drilled at the site to date (P-18D) extended to 68 feet below grade or approximately 167 feet msl (see Figure 2 for boring locations). Limited outcroppings of PWR are present within the active soil borrow area to the south of the active CDLF landfill. The PWR appears to originate from meta-argillite or bedrock and is characterized by closely spaced, steeply dipping foliation and widely spaced joints. Bedding plane and axial plane foliation is closely spaced, steeply dipping and generally strikes approximately N20W to N20E. Joints are likewise steeply dipping, are widely spaced and generally strike N15E to N35E and N35W to N60W based on measurements made at the outcroppings of PWR. The lithology and characteristics of the PWR at the outcrops are consistent with those observed during drilling at the site and with the description of bedrock mapping unit CZmgs (see Section 2.1). It is noted that green, weathered phyllite with wavy sub-vertical foliation and abundant rock fragments was encountered in the borehole of piezometer P-19D below weathered meta-argillite beginning at a depth of approximately 52 feet below grade or approximately elevation 175.5 msl (see Figure 2 for boring locations). The weathered phyllite is consistent with the description of bedrock mapping unit CZmmv (see Section 2.1). 8 4.0 TEST BORINGS AND PIEZOMETERS Fifteen soil borings were drilled within and immediately adjacent to the proposed 17-acre expansion area for the Nash County CDLF. Eleven of the borings were completed as shallow piezometers and four were completed as deep piezometers. Pairs of shallow and deep piezometers were installed at four drilling locations for assessment of vertical potentiometric gradients in the surficial aquifer. In addition, eleven piezometers installed as part of the 1998 Site Suitability Study (including three shallow/deep pairs), and six monitoring wells installed for monitoring groundwater quality in the area of the active CDLF were used as part of this investigation to characterize the hydrogeology of the site. Seven of the previously installed piezometers and monitoring wells are located within or immediately adjacent to the proposed CDLF expansion area. Consequently, the number of boring locations included in this investigation exceeds the requirement of one boring per acre for the Design Hydrogeologic investigation. The locations and designations of the piezometers and monitoring wells are shown in Figure 2. A summary of test boring data, including depths to PWR and termination depths, as well as piezometer/monitoring well construction specifications, is presented in Table 1. Test boring logs and piezometer completion records for borings drilled as part of this investigation are presented in Appendix A. Test boring locations were selected based on topographic features for the purpose of characterizing the lithology of the materials encountered during drilling and ground water conditions within the planned disposal unit footprint and buffer area. The test borings represent subsurface conditions at ridge lines and knolls (high elevations), along drainage bottoms (low elevations) and intermediate slopes (mid-elevations). Piezometer screen intervals were selected to represent the saprolite and PWR formations. As noted in Section 3.3, bedrock was not encountered in soil borings drilled during this or previous investigations. The fifteen test borings drilled during this investigation were drilled with a track-mounted drilling rig equipped with hollow-stem augers (Mobile B-57). Soil samples were collected from the test borings to document the lithology of the subsurface materials penetrated during drilling. The samples were collected in 2-foot intervals at selected depths (generally every five feet) within each boring using 2-feet long, 2-inch inside diameter (ID) steel split-spoon samplers in accordance with standard penetration test (SPT) protocols (ASTM D 1586-84) to provide an index for estimating soil strength and relative density. In conjunction with the penetration testing, thirty split-spoon soil samples were retained for geotechnical laboratory testing (see Section 5.0). The depths from which soil samples were collected from the test borings, lithologic descriptions of the soils penetrated during drilling, as well as piezometer construction details are indicated on the drilling logs included in Appendix A. 9 Each piezometer was installed through the augers to ensure proper construction and placement, and is constructed of 2-inch ID Schedule 40 PVC solid casing and factory slotted well screen (0.01 inch slots) connected by threaded, flush joints. The piezometers were completed to total depths ranging from 30 to 68 feet below grade with 10 feet of well screen equipped with a PVC bottom cap. The solid PVC casing of each piezometer extends from the top of the well screen to approximately 2.5 feet above grade. The annular space of each piezometer is packed with washed sand to a level of approximately 2 feet above the top of the well screen. A minimum one-foot-thick bentonite seal rests on top of the sand pack, above which a Portland cement grout extends to approximately 6 inches below grade. The PVC casing of each piezometer is equipped with a sealed, locking cap to prevent unauthorized access. In addition, each piezometer casing is protected with a steel, stick-up well protector with a hinged, locking cap. Each piezometer was installed and constructed in accordance with North Carolina Well Standards. Following installation, the piezometers were developed using a submersible pump to remove sediment from within the piezometer and annular gravel pack, and to facilitate hydraulic connection between the piezometer and surrounding aquifer material. At each piezometer, the pump was lowered below the water table and was periodically raised and lowered through the water column to agitate the water in the piezometer and induce trapped sediment to be released from the sand pack into the piezometer. This process was repeated until the discharge water appeared to be free of suspended sediments. A piezometer survey was conducted by James G. Strickland Land Surveying, P.A. of Nashville, NC, a licensed North Carolina surveyor in September 2013. The survey included measuring the casing elevations and horizontal positions of the piezometers. Vertical elevations were measured to an accuracy of 0.01-feet relative to North American Vertical Datum (NAVD) 88. The points on the PVC casings at which the elevations were measured were permanently marked for future reference. The horizontal positions of the piezometers were measured to the nearest 0.1-foot relative to the North Carolina State Plane (NCSP) coordinate system. Well elevation data are included in Table 1. 10 5.0 LABORATORY GEOTECHNICAL TESTING Laboratory testing of soil samples collected during drilling was conducted as part of the Design Hydrogeologic investigation. The laboratory testing program consisted of the following tests. Test Description ASTM Standard Number of Samples Atterberg Limits D 4318 9 Grain Size w/Hydrometer D 422, D 1140 30 Moisture Content D 2216 9 Of particular relevance to the Design Hydrogeologic investigation are the results of the grain size analyses, which were used to estimate specific yield of the unconsolidated sediments in the surficial aquifer. Laboratory data sheets for the grain size analyses are included in Appendix B. Grain size distribution and soil classification data are presented in Table 2. The soils were classified in the laboratory according the Unified Soil Classification System (USCS). These descriptions were matched to the boring logs to verify the visual soil classifications. Based on the laboratory data, a majority of the on-site soils classify as silt, sandy silt and silt with sand (SM), with occasional elastic silt (MH). Some of the laboratory tested soils exhibited clay content in the range of 5 to 20 percent, which is consistent with field observations (the soils are generally variably clayey silt and sandy silt). Most of the soils submitted for Atterberg Limits testing exhibited low plasticity. One exception is the sample collected from 3.0 to 5.0 feet below grade at boring P-22 which exhibited high plasticity. The sample included significant clay content and is classified as clayey silt. 11 6.0 SITE GEOLOGY AND HYDROGEOLOGY The evaluation of subsurface geology and hydrogeology presented in the following sections is based on published information regarding the regional geological and hydrogeological framework (discussed in Section 2.0) in conjunction with the descriptions of subsurface materials recorded in the drilling logs (Appendix A) and the results of rising-head permeability (“slug”) tests (Section 6.2.1). 6.1 Site Geology Natural subsurface materials encountered during drilling of the piezometer borings are consistent with descriptions of the regional geology presented in the published literature (see Section 2.0) , as well as borings drilled during the previous Site Suitability investigation conducted in 1998 and during installation of groundwater monitoring wells for the currently active CDLF. Four distinct lithologic units were identified at the site during this investigation and the 1998 Site Suitability investigation, each of which is described below. SILT and CLAY: The uppermost unit over most of the study area is comprised of a mixture of low to medium plasticity silt and clay with minor sand which varies in color from red-brown to orange and ranges in thickness from approximately 2 to 12 feet. The silt and clay unit is missing in those areas where extensive soil borrowing has been conducted, in particular in the areas of borings P-20/P-20D, P-22 and P-23 (Figure 2). The silt and clay appears to be soil formed by extensive in-place weathering of the original bedrock, but may also include minor colluvial soils formed on uplands and redeposited on slopes. Silty CLAY: The silty clay unit was not encountered during drilling for this investigation; however, the unit was encountered in piezometer borings drilled in the northwest portion of the study area (P-5D, P-9, P-11D and P-13) during the 1998 Site Suitability investigation. The silty clay unit is generally described as having low to medium plasticity, is red-purple and yellow, orange and tan in color, and is characterized by closely spaced sub-vertical foliation with common black mineralization along foliation and fracture planes. The silty clay unit generally exhibits SPT values ranging from approximately 5 to 60 blows per foot, depending on the degree of weathering and crystalline mineralization along fracture and foliation planes. Where present, the unit ranges in thickness up to 30 feet. Clayey SILT: The clayey silt unit either underlies the silty clay unit or is the uppermost unit in the study area, and was encountered at all drilling locations except P-23 where extensive soil borrowing has been conducted. The unit is distinctly saprolitic with generally conspicuous relict rock fabric and structure that becomes more distinct with depth as the degree of weathering decreases and it transitions to PWR. The unit appears to originate from extensive physical and 12 chemical weathering of the underlying meta-argillite bedrock and is characterized by closely spaced, steeply dipping relict foliation and widely spaced relict joints. Rock fragments are commonly present within the deeper portion of this unit, and well-indurated healed fractures are present throughout the profile, often exhibiting dark mineral staining along the fracture faces at depths below the water table. Horizontal partings are commonly observed superimposed on the sub-vertical foliation, which are likely dynamic fractures formed from unloading processes. Weathered black, brown, white and rust-orange mineral grains are common within this unit. The upper portion of the unit is generally mottled red-brown-orange-tan-gray. Deeper portions of the unit, where relict foliation is more distinct, is generally characterized by alternating, thin red, red-brown, orange, tan and gray laminations in varying combinations. The clayey silt unit generally exhibits SPT values ranging from approximately 20 to 50 blows per foot. Where present, the unit ranges in thickness from 4 (P-26) to greater than 50 feet (P-20D). Partially Weathered Rock (PWR): The PWR unit was encountered in all soil borings except P- 20S, P-20D and P-27. The PWR unit represents a transition zone at the base of the regolith where saprolite grades into unweathered bedrock. As defined herein, the PWR unit is characterized by SPT resistance of greater than 100 blows per foot while still allowing penetration by hollow stem auger drilling. The PWR formed as the result of incomplete weathering in the lower regolith such that chemical alteration of the bedrock has not progressed to a stage where clay and other weathering by-products have been formed in sufficient quantities to completely fill fractures and other secondary openings. Most of the PWR encountered at the site is dense weathered meta-argillite (manifested as clayey silt) characterized by closely spaced sub-vertical foliation, widely spaced relict high angle fractures, horizontal partings superimposed on the foliation, and abundant rock fragments which increase in abundance with depth. The unit is generally variably colored brown, gray, orange, red and/or tan, with some sections exhibiting alternating gray-red-orange or gray-brown-tan laminations. The PWR was encountered at depths ranging from the ground surface (P-23) where extensive soil borrowing has been conducted to 43 feet below grade (P-21D) near the northeast area of the proposed CDLF. The PWR unit was not encountered at P-20D where drilling extended to 50 feet below grade. The thickness of the PWR unit was not determined during this investigation because the surface of unweathered bedrock was not encountered during drilling. A change in lithology of the PWR to weathered meta-phyllite (manifested as silt) was encountered in boring P-19D beginning at a depth of 52 feet below grade and extending to the total depth of the boring (60 feet below grade). The weathered meta-phyllite is emerald green in color and is characterized by a high chlorite content, closely spaced wavy sub-vertical foliation manifesting relict flow texture, and abundant rock fragments. The lithology and characteristics of the meta-phyllite encountered during drilling are consistent with the description of bedrock mapping unit CZmmv (see Section 2.1). 13 Generalized geologic cross-sections in which graphical representations of the lithologic units encountered during drilling are depicted are presented as Figures 4, 5 and 6. The locations of the cross section lines are shown in Figure 2. The cross sections depict the subsurface distribution of the lithologic units based on drilling logs from piezometer/well borings drilled during this investigation and the 1998 Site Suitability investigation. The cross sections illustrate a generally undulating contact between saprolite and the underlying PWR indicating differential degrees of weathering that are likely the result variations in mineralogy and resistance to weathering of the original parent bedrock. A subsurface pinnacle of PWR appears to be located in the area of boring P-26 where the surface of PWR was encountered at a depth of 8 feet below grade. Similarly, PWR was encountered beginning at the ground surface at the location of boring P-23 where extensive soil borrowing has been conducted. The surface of competent bedrock was not encountered during drilling in this investigation or the 1998 Site Suitability investigation. The deepest borehole drilled at the site to date (P-18D) extended to 68 feet below grade or approximately 167 feet msl (see Figure 2 for boring locations). 6.2 Site Hydrogeology As determined in previous investigations and confirmed as part of this investigation, the surficial aquifer at the site is comprised of the silty clay and clayey silt saprolite and PWR. Groundwater within the surficial aquifer at the site generally occurs under water-table (unconfined) conditions within the interstitial pore spaces and relict foliation and fractures of the saprolite and PWR. The depth to groundwater in the surficial aquifer within the study area during the period of April through September 2013 varied between approximately 5.8 (P-27) and 38.4 (P-26) feet below ground surface. It noted that, with the exception of P-27, which is located outside the boundaries of the planned CDLF expansion area, the depth to groundwater at all other piezometer locations was greater than 14 feet below grade during the observation period. Based on the designed final subgrade of the proposed CDLF expansion depicted in the geologic cross sections (Figures 4, 5 and 6) and the engineering plans included in the accompanying permit documents, the minimum vertical separation requirements in 15A NCAC 13B .0540 (2) (a) between the seasonal high water table as determined herein (see Section 6.2.4) and the final landfill grades are satisfied by the engineering design of the landfill expansion. 6.2.1 Results of Aquifer Tests Rising-head permeability (“slug”) tests were conducted in all of the piezometers installed for the Design Hydrogeologic investigation to estimate the horizontal hydraulic conductivity of the saturated lithologic units within the screen intervals of the piezometers. The slug tests were conducted using a submersible pump in accordance with ASTM D 4044. 14 Static water level measurements were made at each piezometer prior to beginning the slug tests. The slug tests were conducted by placing a combined data recorder/pressure transducer (In-Situ Level Troll™) at the bottom of the piezometer and rapidly lowering the level of water below the level measured at static conditions. The data logger was used to measure the rate of influx of groundwater until water levels reached a minimum of approximately 80% of the static level measured prior to testing. The measured rate of recovery of the water level is a function of the horizontal hydraulic conductivity of the aquifer material in the vicinity of the well. The slug test data was analyzed using the HydroSOLVE, Inc. AQTESOLV for Windows™ program according to the Bouwer-Rice procedure. Estimates of the hydraulic conductivity (K) of the aquifer materials at the locations of the piezometers installed for the hydrogeological characterization were made based on analyses of the water level versus time data collected during the slug tests. The data output and graphs generated by AQTESOLV™ are provided in Appendix C. Calculated values of K based on the slug test data are presented in Table 3. Estimated values of hydraulic conductivity for the shallow surficial aquifer based on the results of the slug tests performed in the 11 new shallow piezometers installed as part of this investigation ranged from 2.26 x 10-5 cm/sec (0.064 ft./day) at piezometer P-25 to 6.51 x 10-3 cm/sec (18.5 ft./day) at piezometer P-27. The geometric mean K for all the shallow piezometers is 5.90 x 10-4 cm/sec (1.67 ft/day). Estimated values of hydraulic conductivity for the deep surficial aquifer based on the results of the slug tests performed in the four new deep piezometers ranged from 3.82 x 10-4 cm/sec (1.08 ft./day) at piezometer P-21D to 2.01 x 10-3 cm/sec (5.71 ft./day) at piezometer P-20D. The geometric mean K for all the deep piezometers is 8.02 x 10-4 cm/sec (2.27 ft/day). The values of hydraulic conductivity determined for the surficial aquifer are similar to those determined by slug tests performed during the 1998 Site Suitability investigation. It is noted that the geometric average K determined for the deep surficial aquifer is approximately five times greater than the geometric average K for the shallow surficial aquifer. This difference is likely due to the lesser degree of weathering and infilling of secondary openings in deeper zones of the surficial aquifer in resulting higher intrinsic permeability. 6.2.2 Short and Long Term Groundwater Elevations Table 4 presents a summary of short-term ground water levels observed at the end of drilling and 24-hours after installation of the piezometers, as well as stabilized groundwater level readings obtained a minimum of seven days after completion of the piezometers. Table 5 presents a summary of long-term groundwater level observations at the piezometers installed for this study, existing piezometers installed for the 1998 Site Suitability investigation, 15 as well as nearby monitoring wells installed to monitor groundwater quality in the vicinity of the currently active CDLF. The groundwater elevation data presented in Table 5 indicate that the majority of the highest groundwater elevations recorded during the monitoring period at the new and previously installed piezometers (23 of 26 locations) occurred during July 2013. This corresponds with unusually high rainfall totals during July in Nash County and surrounding areas. Although only one of the groundwater monitoring wells (MW-3) had a historical high groundwater elevation recorded during July 2013, the historical high groundwater elevations for the remaining monitoring wells average only approximately 1 foot higher than the groundwater elevations measured in July 2013. Moreover, the database of groundwater elevations for the monitoring wells covers a period of 6 ½ years. Therefore, the groundwater elevations measured at the piezometers and monitoring wells during July 2013 are considered good approximations of historical high water-table conditions. Historical climatic trends are published using regional climatic data from the NOAA National Climatic Data Center. A key parameter of interest is the Palmer Hydrologic Drought Index (PHDI), shown below, which is compiled for 15 years of weather records for the northern Coastal Plain region of North Carolina, which includes Nash County. The PHDI represents an overall moisture balance within a region, compiled from multiple weather stations for average precipitation, temperature, evapotranspiration, leaf indices (growing season), wind velocities, and solar radiation. Palmer indices provide a more complete description of climatic trends than precipitation data alone, since evapotranspiration effects are factored into the overall moisture balance in the atmosphere and at the ground surface (i.e., the water availability for ground water recharge). The PHDI graph indicates that drought conditions persisted from mid-1998 through mid-1999 followed by a period of wet conditions ending in early 2001. Drought conditions once again persisted from early 2001 through early 2002 followed by generally wet conditions through mid- 2007. Extreme drought conditions persisted from mid-2007 through late-2009 followed by a period of alternating wet and dry conditions through October 2013. The PHDI graph clearly illustrates the above average moisture conditions which have persisted at the since June 2013. This wet period corresponds to the period during which the highest groundwater elevations at most of the site piezometers were recorded. 16 Approximately 50% of the land area within the borders of the proposed CDLF expansion is devoid of vegetation, having undergone extensive reworking as the result of soil borrowing. These open areas provide recharge zones to the surficial aquifer resulting in a more marked response of the water table to precipitation events than in those areas covered with vegetation where evapotranspiration constrains aquifer recharge. The currently active CDLF lies to the north and west of the proposed CDLF expansion area. The relatively impervious cover soils placed on the active CDLF effectively inhibit infiltration of precipitation thereby greatly inhibiting aquifer recharge. Pig Basket Creek and associated fringing wetlands located east of the proposed CDLF expansion area serve as ground water discharge features at the site, which tend to stabilize groundwater levels. 6.2.3 Horizontal and Vertical Groundwater Flow A water-table elevation contour map for the study area based on groundwater elevation gauging data collected in September 2013 from the shallow piezometers installed as part of this investigation, as well as existing shallow piezometers installed as part of the 1998 Site Suitability investigation and water-table monitoring wells installed to monitor the currently active CDLF, is presented as Figure 7. The geometric configuration of the water-table elevation contours presented in Figure 7 indicate that bulk flow of shallow groundwater at the site is generally to the east-northeast toward Pig Basket Creek, which is consistent with previous delineations of shallow groundwater flow at the site. Based on the groundwater elevation contour map shown in Figure 7, the hydraulic gradient of the water table ranged from approximately 0.002 ft/ft to 0.03 17 ft/ft in September 2013. The geometric mean hydraulic gradient of the water table was approximately 0.011 ft/ft. (see Table 6). Estimates of the horizontal interstitial groundwater flow velocity in the shallow surficial aquifer are presented in Table 6. The flow velocity estimates are based on hydraulic conductivity values derived from slug tests conducted in the piezometers (Section 6.2.1), groundwater elevation data collected on September 30 2013 from the shallow piezometers and monitoring wells, and estimates of effective porosity derived from visual classifications and grain size distribution analyses of selected samples of soil collected from the surficial aquifer. Effective porosity values for soils and sediments are commonly derived using the method of Johnson (1967)6 based on grain size distribution. This method relies on the assumption that specific yield is numerically equivalent to effective porosity. However, not all water-filled pores or secondary openings are interconnected (e.g. “dead-end” or isolated pores) or significantly contribute to bulk flow, but may still be drainable in tests to determine specific yield. More recent research has shown that estimates of effective porosity based on grain size analysis tend to overestimate the numerical value of effective porosity by approximately 80%.7 Consequently, effective porosity values estimated using the method of Johnson (1967) should be considered maximum estimated values. Calculated values of effective porosity are included in Tables 2, 3, and 6. The bulk average interstitial groundwater flow velocity (vw) can be expressed according the relation vw = Ki/ƞe, where K is the horizontal hydraulic conductivity of the aquifer material, i is the hydraulic gradient, and ƞe is the effective porosity of the aquifer material. Calculations of the horizontal groundwater flow velocity are presented in Table 6. Based on the calculations presented in Table 6, the interstitial groundwater flow velocity in the shallow aquifer is estimated to range from 0.004 ft/day (1.46 ft/yr) to 2.59 ft/day (946 ft/yr), with a geometric mean of 0.29 ft/day (65.75 ft/yr). The wide range of groundwater flow velocities calculated for the surficial aquifer (approximately three orders of magnitude) is likely a reflection of differential degrees of weathering within the saprolite and PWR and thereby the abundance of secondary openings available for groundwater flow. It is noted that the majority of groundwater flow occurs through interconnected zones exhibiting the highest permeability. Calculations of average bulk groundwater flow velocity using the 6 A.I. Johnson, 1967, US Geological Survey Water Supply Paper 1662-D, 74 pp. 7 Stephens, D. B., Kuo-Chin Hsu, Mark A. Prieksat, Mark D. Ankeny, Neil Blandford, Tracy L. Roth, James A. Kelsey, and Julia R. Whitworth, 1998, A comparison of estimated and calculated effective porosity, Hydrogeology Journal vol. 6 pp.156-165. 18 method applied herein are not based on a weighted average of volumetric flow through zones of varying permeability. Consequently, the bulk average groundwater flow velocities calculated using this method should be considered minimum values. Moreover, the velocity of groundwater flow through zones of highest permeability may significantly exceed the average calculated values. Vertical potentiometric gradients denote the potential for groundwater to move vertically through an aquifer. Vertical gradients are calculated by dividing the difference in groundwater elevation between two adjacent piezometers with screens installed at different elevations in the saturated interval of interest by the vertical distance between the midpoints of the saturated interval of the well screens. Positive values denote downward vertical gradients whereas negative values denote upward vertical gradients. Table 7 presents estimated vertical groundwater potentiometric gradients for the surficial aquifer based on groundwater gauging data collected during the period of April to September 2013 for piezometer couplets P-18S/18D, P-19S/19D, P-20S/20D, P-21S/21D, P-11/11D and P-15/15D. A comparison of groundwater elevation data between adjacent piezometers provides an indication of vertical groundwater movement within the surficial aquifer. The results of the vertical potentiometric gradient analysis indicate that slight upward gradients were measured during all gauging events for piezometer pair P-18S/18D, ranging in magnitude from 2.21 x 10-2 ft/ft to 3.57 x 10-2 ft/ft. For piezometer pair P-19S/19D, slight downward vertical gradients were measured during all gauging events, ranging in magnitude from 5.64 x 10-3 ft/ft to 4.58 x 10-2 ft/ft. For piezometer pair GM-23/23D, vertical potentiometric gradients were observed to fluctuate from slight downward gradients in April, May and July 2013 (1.47 x 10-3 ft/ft to 2.45 x 10-3 ft/ft) to slight upward gradients in June, August and September 2013 (4.89 x 10-4 ft/ft to 1.47 x 10-3 ft/ft). At piezometer pair P-21S/21D, slight downward vertical gradients were measured during all gauging events, ranging in magnitude from 1.64 x 10-2 ft/ft to 3.68 x 10-2 ft/ft. At piezometer pair P-11/11D, vertical potentiometric gradients were observed to fluctuate from slight downward gradients in April and September 2013 (4.66 x 10-3 ft/ft and 2.66 x 10-2 ft/ft, respectively) to slight upward gradients in June, July and August 2013 (7.59 x 10-3 ft/ft to 1.35 x 10-2 ft/ft). At piezometer pair P-15/15D, slight downward vertical gradients were measured during all gauging events, ranging in magnitude from 1.49 x 10-2 ft/ft to 3.43 x 10-2 ft/ft. The results of the horizontal and vertical potentiometric gradient analyses indicate that bulk groundwater flow within the surficial aquifer is dominated by lateral flow toward Pig Basket Creek and associated fringing wetlands, which are the major groundwater discharge features in 19 the study area. Vertical potentiometric gradients are slight and appear to have little influence on bulk groundwater flow within the proposed CDLF area. 6.2.4 Estimated Seasonal High Water Table As discussed in Section 6.2.2, the groundwater elevation data presented in Table 5 indicate that the majority of the highest groundwater elevations recorded during the monitoring period (April through September 2013) at the new and previously installed piezometers (23 of 26 locations) occurred during July 2013. This corresponds with unusually high rainfall totals during July in Nash County and surrounding areas. Although only one of the groundwater monitoring wells (MW-3) had a historical high groundwater elevation recorded during July 2013, the historical high groundwater elevations for the remaining monitoring wells average only approximately 1 foot higher than the groundwater elevations measured in July 2013. Moreover, the database of groundwater elevations for the monitoring wells covers a period of 6 ½ years. The highest groundwater elevation recorded at each shallow piezometer and monitoring well was selected from the database included in Table 5, regardless of date, to establish the seasonal high water table. A groundwater elevation contour map for the shallow surficial aquifer using the highest groundwater elevation recorded at each piezometer and monitoring well is presented in Figure 8, and is considered to graphically depict the estimated seasonal-high water table for the site. In addition, the seasonal high water table is also graphically depicted in the geologic cross sections in Figures 4, 5, and 6 to depict the vertical relationship between the seasonal high water table and the engineered final subgrade of the proposed CDLF expansion. Based on the designed final subgrade of the proposed CDLF expansion depicted in the geologic cross sections (Figures 4, 5 and 6) and the engineering plans included in the accompanying permit documents, the minimum vertical separation requirements in 15A NCAC 13B .0540 (2) (a) between the seasonal high water table as determined herein and the final landfill subgrade are satisfied by the engineering design of the landfill expansion. 6.2.5 Special Geologic Considerations No unusual geologic features have been determined which would affect groundwater flow or the ability to effectively monitor groundwater quality at the site, including faults, mines or dikes. Site conditions appear typical of the North Carolina Piedmont region. FIGURES Drawn by: Reviewed by: Drawing #: Drawing Date: 1 SITE LOCATION MAP Nash County C&D Landfill Nashville, Nash County, North Carolina Source: USGS 7.5’ Topographic Quadrangle Series Castalia, NC, 2013 and Red Oak, NC 2013 Figure No. Project #: Scale: USGS 1:24,000 09/26/2013 N 11112 Branding Iron Place Wendell, NC 27591 Office: (919) 366-3663 Cell: (919) 995-0363 TABLES Table 1 Test Boring/Piezometer Data Elevation Data Test Boring Data Piezometer Construction Data Boring Boring PVC Pipe Ground Stickup Total Bottom PWR PWR Refusal Refusal Top of Piez. Screen Bottom of Piez. Screen Number Date Elev.(1)Elev.(1)feet Depth, ft.Elevation Depth, ft.Elevation Depth, ft.Elevation Depth, ft.Elev.Depth, ft.Elev. P-18S 3/27-28/2013 237.36 235.01 2.36 40.0 195.01 28.5 206.51 NA NA 30.00 205.01 40.00 195.01 Saprolite P-18D 3/27/2013 237.46 235.10 2.36 68.0 167.10 28.5 206.60 NA NA 58.00 177.10 68.00 167.10 PWR P-19S 3/28/2013 230.16 227.94 2.22 40.0 187.94 33.5 194.44 NA NA 30.00 197.94 40.00 187.94 Saprolite/PWR P-19D 3/28/2013 230.03 227.54 2.49 60.0 167.54 33.5 194.04 NA NA 50.00 177.54 60.00 167.54 PWR P-20S 4/2/2013 216.22 213.52 2.70 30.0 183.52 NA NA NA NA 20.00 193.52 30.00 183.52 Saprolite P-20D 4/2/2013 215.59 213.07 2.52 52.0 161.07 NA NA NA NA 40.00 173.07 50.00 163.07 Saprolite P-21S 4/3/2013 219.90 217.59 2.31 40.0 177.59 43.0 174.59 NA NA 30.00 187.59 40.00 177.59 Saprolite P-21D 4/3/2013 220.17 217.54 2.63 60.0 157.54 43.0 174.54 NA NA 50.00 167.54 60.00 157.54 PWR P-22 3/26/2013 238.62 236.23 2.38 52.0 184.23 24.5 211.73 NA NA 40.00 196.23 50.00 186.23 PWR P-23 3/27/2013 240.38 237.66 2.72 40.0 197.66 0.0 237.66 NA NA 28.00 209.66 38.00 199.66 PWR P-24 4/1/2013 232.15 229.42 2.74 57.0 172.42 19.0 210.42 NA NA 45.00 184.42 55.00 174.42 PWR P-25 4/1-2/2013 229.29 227.17 2.12 55.0 172.17 29.0 198.17 NA NA 50.00 177.17 60.00 167.17 PWR P-26 3/25/2013 237.36 234.69 2.67 47.0 187.69 8.0 226.69 NA NA 35.00 199.69 45.00 189.69 PWR P-27 3/26/2013 202.20 199.92 2.28 30.0 169.92 NA NA NA NA 20.00 179.92 30.00 169.92 Saprolite P-28 3/26/2013 226.19 223.28 2.91 47.0 176.28 41.5 181.78 NA NA 35.00 188.28 45.00 178.28 Saprolite/PWR Table 1B Supplemental Test Boring Data Elevation Data Test Boring Data Piezometer Construction Data Boring Boring PVC Pipe Ground Stickup Total Bottom PWR PWR Refusal Refusal Top of Piez. Screen Bottom of Piez. Screen Number Date Elev.(1)Elev.(1)feet Depth, ft.Elevation Depth, ft.Elevation Depth, ft.Elevation Depth, ft.Elev.Depth, ft.Elev. MW-1 Unknown 244.07 NA NA 41.1 NA NA NA NA NA 21.10 NA 41.10 NA NA MW-2 Unknown 236.08 NA NA 32.2 NA NA NA NA NA 17.20 NA 32.20 NA NA MW-3 Unknown 231.36 NA NA 37.1 NA NA NA NA NA 22.10 NA 37.10 NA NA MW-4 Unknown 229.51 NA NA 41.8 NA NA NA NA NA 21.80 NA 41.80 NA NA MW-5 Unknown 237.28 NA NA 51.2 NA NA NA NA NA 36.20 NA 51.20 NA NA MW-6 Unknown 221.09 NA NA 41.9 NA NA NA NA NA 26.90 NA 41.90 NA NA P-3 02/17/98 224.20 221.67 2.54 38.0 183.7 NA NA NA NA 28.00 193.67 38.00 183.67 Saprolite P-5 02/18/98 244.29 242.00 2.29 30.0 212.0 NA NA NA NA 15.00 227.00 30.00 212.00 Saprolite P-5D 02/18/98 244.09 241.82 2.27 48.0 193.8 NA NA NA NA 43.00 198.82 48.00 193.82 Saprolite P-8 02/10/98 222.14 219.71 2.43 48.0 171.7 29.00 190.71 NA NA 28.00 191.71 48.00 171.71 PWR P-9 02/11/98 243.56 241.27 2.29 33.0 208.3 NA NA NA NA 23.00 218.27 33.00 208.27 Saprolite P-11 02/24/98 230.67 228.12 2.55 25.0 203.1 NA NA NA NA 15.00 213.12 25.00 203.12 Saprolite P-11D 02/24/98 229.67 227.86 1.81 48.0 179.9 NA NA NA NA 42.00 185.86 47.00 180.86 Saprolite P-13 02/25/98 230.80 227.92 2.88 20.0 207.9 NA NA NA NA 10.00 217.92 20.00 207.92 Saprolite P-15 02/10/98 218.57 217.46 1.11 22.0 195.5 NA NA NA NA 12.00 205.46 22.00 195.46 Saprolite P-15D 02/10/98 220.18 217.61 2.57 48.0 169.6 24.00 193.61 NA NA 28.00 189.61 48.00 169.61 PWR P-16D 02/19/98 219.31 216.84 2.47 43.0 173.84 38.00 178.84 NA NA 33.0 183.84 43.0 173.84 Saprolite/PWR Notes:1. Ground elevations based on survey performed September 2013 2. All depths referenced from ground surface Saturated saprolite, typically <100 blows per foot (typically penetrated by hollow stem auger) Saturated PWR, typically >100 blows per foot (typically penetrated by hollow stem auger) Hydrogeologic Unit Hydrogeologic Unit Table 2 Geotechnical Laboratory Data Grain Size Distribution and Unified Soil Classification Boring Sample % Gravel %Sand %Silt/Clay Liquid Plasticity Natural Effective USCS Lithologic Number Depth, ft.>4.75 mm 4.75 -- 0.075 mm <0.075 mm Limit Index Moisture Porosity Classification Description1 P-18D 8.0 - 10.0 0.00 5.85 94.15 45%12%28.3%NA ML Clayey SILT P-18D 18.0 - 20.0 0.00 11.70 88.30 NA NA NA NA ML SILT P-18D 33.0 - 35.0 0.00 13.32 86.68 NA NA NA 11.5%ML SILT P-18D 63.0 - 65.0 0.00 9.44 90.56 NA NA NA 8.0%ML SILT P-19D 8.0 - 10.0 1.97 9.23 88.80 NA NA NA NA ML SILT P-19D 23.0 - 25.0 1.55 10.61 87.84 51%17%28.7%NA MH SILT P-19D 33.0 - 35.0 0.00 8.58 91.42 NA NA NA 9.5%ML SILT P-19D 53.0 -55.0 0.81 19.09 80.10 NA NA NA 16.0%ML Sandy SILT P-20D 0.0 - 3.0 0.07 5.45 94.48 NA NA NA NA ML SILT P-20D 13.0 - 15.0 0.00 1.45 98.55 40%7%29.8%NA ML SILT P-20D 23.0 - 25.0 0.00 5.69 94.31 41%5%30.3%5.0%ML SILT P-20D 28.0 - 30.0 0.00 10.12 89.88 41%6%39.9%6.0%ML SILT P-20D 43.0 - 45.0 0.00 17.2 82.80 NA NA NA 12.0%ML Sandy SILT P-21D 13.0 - 15.0 0.00 17.82 82.18 52%9%45.8%NA MH Sandy SILT P-21D 33.0 - 35.0 0.00 6.57 93.43 53%12%34.3%7.0%MH SILT P-21D 55.0 - 57.0 0.00 33.27 66.73 NA NA NA 16.5%ML Sandy SILT P-22 3.0 - 5.0 0.00 4.23 95.77 78%31%34.6%NA MH Clayey SILT P-22 18.0 - 22.0 0.00 8.59 91.41 NA NA NA NA ML Clayey SILT P-22 43.0 - 45.0 0.00 12.65 87.35 NA NA NA 8.0%ML Clayey SILT P-23 33.0 - 35.0 2.02 17.98 80.00 NA NA NA 13.0%ML Sandy SILT P-24 13.0 - 15.0 0.10 5.96 93.94 NA NA NA NA ML SILT P-24 48.0 - 50.0 0.00 5.02 94.98 NA NA NA 7.5%ML SILT P-25 8.0 - 10.0 0.00 9.53 90.47 NA NA NA NA ML SILT P-25 53.0 - 55.0 3.68 33.66 62.66 NA NA NA 18.0%ML Sandy SILT P-26 38.0 - 40.0 19.12 35.86 45.02 NA NA NA 21.0%SM Silty SAND w/Gravel P-27 23.0 - 25.0 0.00 15.56 84.44 NA NA NA 14.0%ML Sandy SILT P-27 28.0 - 30.0 0.00 20 80.00 NA NA NA 15.0%ML Sandy SILT P-28 8.0 - 10.0 0.87 7.21 91.92 NA NA NA NA ML SILT P-28 38.0 - 40.0 0.00 20.73 79.27 56%10%39.3%7.0%MH Sandy SILT P-28 45.0 - 47.0 0.00 10.63 89.37 NA NA NA 10.0%ML Clayey SILT Notes to Above:Effective porosity values calculated from Textural Classification Triangle method referenced to A.I. Johnson, US Geological Survey Water Supply Paper 1662-D, 1967 (after C.W. Fetter, Applied Hydrogeology, 3rd ed. 1988) 1 - USCS lithologic description based on grain size with hydrometer analysis Table 3 Hydrogeologic Properties of Lithologic Units Piezometer Hydrological Hydrogeological Effective Hydraulic Conductivity (k) Number Unit(1)Description Porosity (2)ft/min ft/day cm/sec Shallow Piezometers P-18S Saprolite Sl. Clayey SILT 11.5%9.92E-05 1.43E-01 5.04E-05 P-19S Saprolite/PWR Sl. Clayey SILT 9.5%4.37E-03 6.29E+00 2.22E-03 P-20S Saprolite Sl. Clayey SILT 5.5%8.38E-03 1.21E+01 4.26E-03 P-21S Saprolite Sl. Clayey SILT 7.0%5.73E-04 8.26E-01 2.91E-04 P-22 PWR Clayey SILT 8.0%6.89E-03 9.92E+00 3.50E-03 P-23 PWR Sandy SILT 13.0%7.87E-03 1.13E+01 4.00E-03 P-24 PWR Sl. Clayey SILT 7.5%2.55E-04 3.67E-01 1.29E-04 P-25 PWR Sandy SILT 18.0%4.45E-05 6.40E-02 2.26E-05 P-26 PWR Silty SAND w/Gravel 21.0%8.05E-04 1.16E+00 4.09E-04 P-27 Saprolite Sandy SILT 14.5%1.28E-02 1.85E+01 6.51E-03 P-28 Saprolite/PWR Sandy SILT 8.5%3.92E-04 5.65E-01 1.99E-04 1.16E-03 1.67E+00 5.90E-04 Deep Piezometers P-18D PWR SILT 8.0%1.42E-03 2.04E+00 7.20E-04 P-19D PWR SILT 16.0%1.47E-03 2.12E+00 7.48E-04 P-20D Saprolite Sandy SILT 12.0%3.96E-03 5.70E+00 2.01E-03 P-21D PWR Sandy SILT 16.5%7.51E-04 1.08E+00 3.82E-04 1.58E-03 2.27E+00 8.02E-04 Notes Slug test data acquisition and data reduction performed by Nautilus Geologic Consulting, PLLC (1)Saprolite - SPT <100 bpf. PWR - partially weathered rock; generally with SPT values in excess of 100 bpf. (2)Effective porosity values for soils assigned based on laboratory testing (see Table 2) (soils in contact with well screen interval taken into consideration) Geometric Mean Geometric Mean Table 4 Short-Term Ground Water Level Observations Boring Boring PVC Pipe Ground Time of Boring Readings 24-hour Readings Stabilized Readings Number Date Elevation Elevation Depth, ft. BGS Elev.Depth, ft. TOC Elev.Depth, ft. TOC Elev. P-18S 3/27-28/2013 237.36 235.01 38.00 197.01 28.34 209.02 27.85 209.51 P-18D 3/27/2013 237.46 235.10 38.00 197.10 27.65 209.81 27.07 210.39 P-19S 3/28/2013 230.16 227.94 37.00 190.94 16.80 213.36 17.07 213.09 P-19D 3/28/2013 230.03 227.54 37.00 190.54 17.34 212.69 17.10 212.93 P-20S 4/2/2013 216.22 213.52 22.00 191.52 20.90 195.32 20.98 195.24 P-20D 4/2/2013 215.59 213.07 22.00 191.07 20.30 195.29 20.40 195.19 P-21S 4/3/2013 219.90 217.59 39.00 178.59 25.80 194.10 26.64 193.26 P-21D 4/3/2013 220.17 217.54 39.00 178.54 26.40 193.77 25.36 194.81 P-22 3/26/2013 238.62 236.23 42.00 194.23 33.62 205.00 32.94 205.68 P-23 3/27/2013 240.38 237.66 32.00 205.66 21.00 219.38 20.93 219.45 P-24 4/1/2013 232.15 229.42 47.00 182.42 35.20 196.95 34.79 197.36 P-25 4/1-2/2013 229.29 227.17 48.00 179.17 52.90 176.39 31.35 197.94 P-26 3/25/2013 237.36 234.69 38.00 196.69 40.42 196.94 40.07 197.29 P-27 3/26/2013 202.20 199.92 18.00 181.92 8.87 193.33 8.70 193.50 P-28 3/26/2013 226.19 223.28 30.00 193.28 33.83 192.36 34.28 191.91 Stabilized water levels acquired a minimum of 7 days after completion of drilling at each location. Top of Casing (TOC)Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Series Well ID Northing Easting ft, MSL (ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL) MW-1 840915.56 2293133.46 244.07 18.26 225.81 34.50 209.57 22.31 221.76 34.42 209.65 21.28 222.79 35.33 208.74 MW-2 841592.39 2293373.35 236.08 17.44 218.64 30.84 205.24 19.40 216.68 29.85 206.23 19.42 216.66 30.15 205.93 MW-3 841873.93 2293520.44 231.36 23.35 208.01 34.60 196.76 24.39 206.97 32.69 198.67 24.76 206.60 33.63 197.73 MW-4 841932.36 2293915.44 229.51 32.15 197.36 36.25 193.26 33.13 196.38 35.93 193.58 33.45 196.06 36.1 193.41 MW-5 841784.14 2294163.97 237.28 39.65 197.63 44.16 193.12 40.55 196.73 43.97 193.31 41.01 196.27 44.31 192.97 MW-6 841385.88 2294169.51 221.09 23.35 197.74 29.22 191.87 23.67 197.42 28.22 192.87 24.33 196.76 28.69 192.40 P-3 842124.21 2293877.91 224.20 ------------------------------------ P-5 841143.81 2293412.92 244.29 ------------------------------------ P-5D 841152.57 2293426.55 244.09 ------------------------------------ P-8 840143.36 2294277.26 222.14 ------------------------------------ P-9 841254.29 2293101.61 243.56 ------------------------------------ P-11 841723.46 2293357.33 230.67 ------------------------------------ P-11D 841728.95 2293356.05 229.67 ------------------------------------ P-13 841964.59 2293430.05 230.80 ------------------------------------ P-15 840398.14 2294336.87 218.57 ------------------------------------ P-15D 840401.53 2294341.84 220.18 ------------------------------------ P-16D 841431.62 2294214.80 219.31 ------------------------------------ P-18d 840841.86 2293648.94 237.46 ------------------------------------ P-18s 840853.84 2293656.55 237.36 ------------------------------------ P-19d 840490.69 2293872.91 230.03 ------------------------------------ P-19s 840498.14 2293868.68 230.16 ------------------------------------ P-20d 841124.76 2294391.01 215.59 ------------------------------------ P-20s 841127.11 2294382.38 216.22 ------------------------------------ P-21d 841464.22 2294425.97 220.17 ------------------------------------ P-21s 841459.24 2294420.42 219.90 ------------------------------------ P-22 841043.42 2293610.43 238.62 ------------------------------------ P-23 840883.75 2293361.32 240.38 ------------------------------------ P-24 840763.07 2294163.72 232.15 ------------------------------------ P-25 840599.53 2294412.15 229.29 ------------------------------------ P-26 841066.33 2294084.21 237.36 ------------------------------------ P-27 841347.82 2294688.18 202.20 ------------------------------------ P-28 841695.10 2294398.76 226.19 ------------------------------------ Notes:Maximum groundwater elevations highlighted in yellow. Only stabilized groundwater elevations were used in determining maximum values. Table 5 Long-Term Ground Water Level Observations All groundwater levels referenced from Top of Casing (TOC) C& D L F E x p a n s i o n P i e z o m e t e r s ( 2 0 1 3 ) Ex i s t i n g C & D L F De s i g n H y d r o S t u d y P i e z o m e t e r s (1 9 9 8 ) Ex i s t i n g C & D L F Mo n i t o r i n g W e l l s 5/17/2007 11/6/2007 5/13/2008 12/21/2008 5/6/2009 11/18/2009 Page 1 of 3 Series Well ID MW-1 MW-2 MW-3 MW-4 MW-5 MW-6 P-3 P-5 P-5D P-8 P-9 P-11 P-11D P-13 P-15 P-15D P-16D P-18d P-18s P-19d P-19s P-20d P-20s P-21d P-21s P-22 P-23 P-24 P-25 P-26 P-27 P-28 Table 5 Long-Term Ground Water Level Observations All groundwater levels referenced from Top of Casing (TOC) C& D L F E x p a n s i o n P i e z o m e t e r s ( 2 0 1 3 ) Ex i s t i n g C & D L F De s i g n H y d r o S t u d y P i e z o m e t e r s (1 9 9 8 ) Ex i s t i n g C & D L F Mo n i t o r i n g W e l l s Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev (ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL) 17.95 226.12 31.24 212.83 24.79 219.28 29.05 215.02 29.05 215.02 27.89 216.18 ------21.00 223.07 16.88 219.20 28.11 207.97 22.77 213.31 25.78 210.30 25.78 210.30 25.35 210.73 ------19.11 216.97 22.78 208.58 31.38 199.98 27.01 204.35 29.19 202.17 29.19 202.17 28.77 202.59 ------24.59 206.77 32.49 197.02 35.69 193.82 34.25 195.26 34.82 194.69 34.82 194.69 34.69 194.82 ------33.59 195.92 39.92 197.36 43.73 193.55 42.05 195.23 42.74 194.54 42.74 194.54 42.78 194.50 ------41.37 195.91 23.20 197.89 28.01 193.08 25.60 195.49 26.46 194.63 26.46 194.63 26.66 194.43 ------24.78 196.31 ------------------------------------------22.94 201.26 ------------------------------------------27.12 217.17 ------------------------------------------28.58 215.51 ------------------------------------------18.34 203.80 ------------------------------------------23.71 219.85 ------------------------------------------19.03 211.64 ------------------------------------------18.14 211.53 ------------------------------------------22.74 208.06 ------------------------------------------16.14 202.43 ------------------------------------------18.31 201.87 ------------------------------------------25.47 193.84 ------------------------------------27.4 210.06 27.07 210.39 ------------------------------------28.3 209.06 27.85 209.51 ------------------------------------17.3 212.73 17.10 212.93 ------------------------------------16.5 213.66 17.07 213.09 ------------------------------------20.3 195.29 20.40 195.19 ------------------------------------20.9 195.32 20.98 195.24 ------------------------------------26.4 193.77 26.36 193.81 ------------------------------------25.8 194.10 25.64 194.26 ------------------------------------33.4 205.22 32.94 205.68 ------------------------------------21.1 219.28 20.93 219.45 ------------------------------------35.2 196.95 34.79 197.36 ------------------------------------52.9 176.39 31.35 197.94 ------------------------------------27.9 209.46 40.07 197.29 ------------------------------------8.9 193.30 8.70 193.50 ------------------------------------------34.28 191.91 Notes:Maximum groundwater elevations highlighted in yellow. Only stabilized groundwater elevations were used in determining maximum values. 5/14/2012 4/26/201311/8/2012 4/4/20135/6/2010 11/19/2010 5/10/2011 11/14/2011 Page 2 of 3 Series Well ID MW-1 MW-2 MW-3 MW-4 MW-5 MW-6 P-3 P-5 P-5D P-8 P-9 P-11 P-11D P-13 P-15 P-15D P-16D P-18d P-18s P-19d P-19s P-20d P-20s P-21d P-21s P-22 P-23 P-24 P-25 P-26 P-27 P-28 Table 5 Long-Term Ground Water Level Observations All groundwater levels referenced from Top of Casing (TOC) C& D L F E x p a n s i o n P i e z o m e t e r s ( 2 0 1 3 ) Ex i s t i n g C & D L F De s i g n H y d r o S t u d y P i e z o m e t e r s (1 9 9 8 ) Ex i s t i n g C & D L F Mo n i t o r i n g W e l l s Maximum Minimum Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev Depth to GW GW Elev (ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL)(ft BTOC)(ft, MSL) 21.05 223.02 21.31 222.76 19.15 224.92 23.09 220.98 26.51 217.56 226.12 208.74 25.35 210.73 19.40 216.68 17.44 218.64 20.88 215.20 23.62 212.46 219.20 205.24 24.75 206.61 24.30 207.06 22.38 208.98 NR NR NR NR 208.98 196.76 33.57 195.94 33.69 195.82 33.19 196.32 33.77 195.74 34.33 195.18 197.36 193.26 41.35 195.93 41.58 195.70 40.98 196.30 41.69 195.59 42.42 194.86 197.63 192.97 25.20 195.89 25.28 195.81 24.35 196.74 25.74 195.35 26.91 194.18 197.89 191.87 ------30.25 193.95 29.86 194.34 30.25 193.95 30.63 193.57 201.26 193.57 ------26.99 217.30 25.26 219.03 27.63 216.66 29.55 214.74 219.03 214.74 ------28.33 215.76 26.79 217.30 28.67 215.42 31.16 212.93 217.30 212.93 ------18.53 203.61 18.12 204.02 19.46 202.68 20.65 201.49 204.02 201.49 ------24.07 219.49 21.31 222.25 25.83 217.73 29.24 214.32 222.25 214.32 ------20.18 210.49 18.30 212.37 22.10 208.57 23.34 207.33 212.37 207.33 ------19.00 210.67 16.97 212.70 20.82 208.85 22.92 206.75 212.70 206.75 ------22.90 207.90 21.06 209.74 22.84 207.96 22.84 207.96 209.74 207.90 ------16.10 202.47 15.57 203.00 16.94 201.63 18.76 199.81 203.00 199.81 ------18.37 201.81 17.85 202.33 18.83 201.35 20.65 199.53 202.33 199.53 ------26.19 193.12 25.30 194.01 26.77 192.54 27.65 191.66 194.01 191.66 26.95 210.51 27.00 210.46 26.12 211.34 27.31 210.15 29.13 208.33 211.34 208.33 27.72 209.64 27.73 209.63 26.89 210.47 27.93 209.43 29.65 207.71 210.47 207.71 17.02 213.01 17.72 212.31 16.70 213.33 19.91 210.12 22.11 207.92 213.33 207.92 17.00 213.16 17.74 212.42 16.70 213.46 19.90 210.26 22.11 208.05 213.46 208.05 20.36 195.23 20.32 195.27 19.64 195.95 20.56 195.03 21.72 193.87 195.95 193.87 20.95 195.27 20.96 195.26 20.23 195.99 21.22 195.00 22.70 193.52 195.99 193.52 26.45 193.72 26.50 193.67 25.76 194.41 27.28 192.89 28.71 191.46 194.41 191.46 25.81 194.09 25.81 194.09 24.86 195.04 26.65 193.25 27.70 192.20 195.04 192.20 32.75 205.87 32.60 206.02 31.75 206.87 32.50 206.12 33.96 204.66 206.87 204.66 20.76 219.62 20.88 219.50 19.12 221.26 22.03 218.35 25.06 215.32 221.26 215.32 34.65 197.50 34.80 197.35 33.57 198.58 34.12 198.03 36.00 196.15 198.58 196.15 31.13 198.16 30.92 198.37 29.34 199.95 29.91 199.38 31.71 197.58 199.95 197.58 40.06 197.30 40.15 197.21 39.32 198.04 39.85 197.51 41.06 196.30 198.04 196.30 8.49 193.71 8.11 194.09 8.13 194.07 8.52 193.68 9.09 193.11 194.09 193.11 34.38 191.81 35.00 191.19 34.51 191.68 35.98 190.21 36.87 189.32 191.91 189.32 Notes:Maximum groundwater elevations highlighted in yellow. Only stabilized groundwater elevations were used in determining maximum values. GW Elev (ft, MSL) 9/30/20137/29/20135/8/2013 6/28/2013 8/30/2013 Page 3 of 3 Table 6 Horizontal Groundwater Gradient and Velocity Calculations Well/Piez.Hydrogeologic Hydraulic Conductivity (k)Grd. Water Reference delta-Elev.Map Length Hydraulic Effective GW Velocity Geometric Mean No.Unit ft/min ft/day cm/sec Elevation*Elevation*in feet in feet Gradient (I)Porosity (n)(V), ft/day Velocity, ft/day Shallow Piezometers P-18S Saprolite 9.92E-05 1.43E-01 5.04E-05 207.71 206 1.71 62.46 0.027 0.115 0.034 P-19S Saprolite/PWR 4.37E-03 6.29E+00 2.22E-03 208.05 206 2.05 74.89 0.027 0.095 1.816 P-20S Saprolite 8.38E-03 1.21E+01 4.26E-03 193.52 194 0.48 61.29 0.008 0.055 1.735 P-21S Saprolite 5.73E-04 8.26E-01 2.91E-04 192.20 192 0.20 59.20 0.003 0.070 0.040 P-22 PWR 6.89E-03 9.92E+00 3.50E-03 204.66 204 0.66 45.74 0.014 0.080 1.778 P-23 PWR 7.87E-03 1.13E+01 4.00E-03 215.32 214 1.32 44.42 0.030 0.130 2.593 P-24 PWR 2.55E-04 3.67E-01 1.29E-04 196.15 196 0.15 82.95 0.002 0.075 0.009 P-25 PWR 4.45E-05 6.40E-02 2.26E-05 197.58 198 0.42 41.27 0.010 0.180 0.004 P-26 PWR 8.05E-04 1.16E+00 4.09E-04 196.30 196 0.30 27.81 0.011 0.210 0.060 P-27 Saprolite 1.28E-02 1.85E+01 6.51E-03 193.11 192 1.11 117.47 0.009 0.145 1.202 P-28 Saprolite/PWR 3.92E-04 5.65E-01 1.99E-04 189.32 190 0.68 32.84 0.021 0.085 0.137 0.18 Notes:Ground Water Velocity Calculated from Equation V=KI/n where K = Hydraulic Conductivity in units of ft/day I = Hydraulic Gradient in units of ft/ft n = Effective Porosity (unitless) Hydraulic Conductivity values from aquifer slug testing using the Bouwer-Rice method Hydraulic Conductivity Conversion Factor: 1 ft/day = 3.59E-04 cm/sec Hydraulic Gradient values were calculated from the potentiometric surface map Effective Porosity values derived from Table 2 *Ground water elevations and potentiometric surfaces for reference elevations derived from water level observations made 9/30/2013 Page 1 of 2 Table 7 Vertical Ground Water Gradient Calculations Data Presented for Selected Dates of Ground Water Observation Nested Piezometers:P-18S P-18D Piezometer Top of Bottom of 4/4/2013 4/26/2013 5/8/2013 6/28/2013 7/29/2013 8/30/2013 9/30/2013 No.Screen Elev.Screen Elev.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E. P-18S 205.01 195.01 209.06 209.51 209.64 209.63 210.47 209.43 207.71 P-18D 177.10 167.10 210.06 210.39 210.51 210.46 211.34 210.15 208.33 midpoint saturated interval -upper 200.01 200.01 200.01 200.01 200.01 200.01 200.01 midpoint saturated interval - lower 172.10 172.10 172.10 172.10 172.10 172.10 172.10 delta-saturated interval 27.90 27.90 27.90 27.90 27.90 27.90 27.90 delta-W.T.E. (see note 1)-9.96E-01 -8.76E-01 -8.66E-01 -8.26E-01 -8.66E-01 -7.16E-01 -6.16E-01 Vertical Gradient (see note 2)-3.57E-02 -3.14E-02 -3.10E-02 -2.96E-02 -3.10E-02 -2.57E-02 -2.21E-02 Up Up Up Up Up Up Up Nested Piezometers:P-19S P-19D Piezometer Top of Bottom of 4/4/2013 4/26/2013 5/8/2013 6/28/2013 7/29/2013 8/30/2013 9/30/2013 No.Screen Elev.Screen Elev.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E. P-19S 197.94 187.94 213.66 213.09 213.16 212.42 213.46 210.26 208.05 P-19D 177.54 167.54 212.73 212.93 213.01 212.31 213.33 210.12 207.92 midpoint saturated interval -upper 192.94 192.94 192.94 192.94 192.94 192.94 192.94 midpoint saturated interval - lower 172.54 172.54 172.54 172.54 172.54 172.54 172.54 delta-saturated interval 20.40 20.40 20.40 20.40 20.40 20.40 20.40 delta-W.T.E. (see note 1)9.35E-01 1.65E-01 1.55E-01 1.15E-01 1.35E-01 1.45E-01 1.35E-01 Vertical Gradient (see note 2)4.58E-02 8.09E-03 7.60E-03 5.64E-03 6.62E-03 7.11E-03 6.62E-03 Down Down Down Down Down Down Down Nested Piezometers:P-20S P-20D Piezometer Top of Bottom of 4/4/2013 4/26/2013 5/8/2013 6/28/2013 7/29/2013 8/30/2013 9/30/2013 No.Screen Elev.Screen Elev.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E. P-20S 193.52 183.52 195.32 195.24 195.27 195.26 195.99 195.00 193.52 P-20D 173.07 163.07 195.29 195.19 195.23 195.27 195.95 195.03 193.87 midpoint saturated interval -upper 188.52 188.52 188.52 188.52 188.52 188.52 188.52 midpoint saturated interval - lower 168.07 168.07 168.07 168.07 168.07 168.07 168.07 delta-saturated interval 20.45 20.45 20.45 20.45 20.45 20.45 20.45 delta-W.T.E. (see note 1)3.00E-02 5.00E-02 4.00E-02 -1.00E-02 4.00E-02 -3.00E-02 -3.00E-02 Vertical Gradient (see note 2)1.47E-03 2.45E-03 1.96E-03 -4.89E-04 1.96E-03 -1.47E-03 -1.47E-03 Down Down Down Up Down Up Up Page 2 of 2 Table 7 Vertical Ground Water Gradient Calculations Nested Piezometers:P-21S P-21D Piezometer Top of Bottom of 4/4/2013 4/26/2013 5/8/2013 6/28/2013 7/29/2013 8/30/2013 9/30/2013 No.Screen Elev.Screen Elev.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E. P-21S 187.59 177.59 194.10 194.26 194.09 194.09 195.04 193.25 192.20 P-21D 167.54 157.54 193.77 193.81 193.72 193.67 194.41 192.89 191.46 midpoint saturated interval -upper 182.59 182.59 182.59 182.59 182.59 182.59 182.59 midpoint saturated interval - lower 162.54 162.54 162.54 162.54 162.54 162.54 162.54 delta-saturated interval 20.05 20.05 20.05 20.05 20.05 20.05 20.05 delta-W.T.E. (see note 1)3.28E-01 4.48E-01 3.68E-01 4.18E-01 6.28E-01 3.58E-01 7.38E-01 Vertical Gradient (see note 2)1.64E-02 2.23E-02 1.84E-02 2.08E-02 3.13E-02 1.79E-02 3.68E-02 Down Down Down Down Down Down Down Nested Piezometers:P-11 P11D Piezometer Top of Bottom of 4/26/2013 6/28/2013 7/29/2013 8/30/2013 9/30/2013 No.Screen Elev.Screen Elev.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E. P-11 213.12 203.12 211.64 210.49 212.37 208.57 207.33 P11D 185.86 180.86 211.53 210.67 212.70 208.85 206.75 midpoint saturated interval -upper 207.38 206.81 207.75 205.85 205.23 midpoint saturated interval - lower 183.36 183.36 183.36 183.36 183.36 delta-saturated interval 24.02 23.45 24.39 22.49 21.87 delta-W.T.E. (see note 1)1.12E-01 -1.78E-01 -3.28E-01 -2.78E-01 5.82E-01 Vertical Gradient (see note 2)4.66E-03 -7.59E-03 -1.35E-02 -1.24E-02 2.66E-02 Down Up Up Up Down Nested Piezometers:P-15 P-15D Piezometer Top of Bottom of 4/26/2013 6/28/2013 7/29/2013 8/30/2013 9/30/2013 No.Screen Elev.Screen Elev.W.T.E.W.T.E.W.T.E.W.T.E.W.T.E. P-15 205.46 195.46 202.43 202.47 203.00 201.63 199.81 P-15D 189.61 169.61 201.87 201.81 202.33 201.35 199.53 midpoint saturated interval -upper 198.94 198.96 199.23 198.54 197.63 midpoint saturated interval - lower 179.61 179.61 179.61 179.61 179.61 delta-saturated interval 19.33 19.35 19.62 18.93 18.02 delta-W.T.E. (see note 1)5.62E-01 6.62E-01 6.72E-01 2.82E-01 2.82E-01 Vertical Gradient (see note 2)2.91E-02 3.42E-02 3.43E-02 1.49E-02 1.56E-02 Down Down Down Down Down Notes to Above: 1 delta-W.T.E. = difference in water level (shallow well minus deep well) 2 Vertical Gradient = delta-W.T.E. / delta-Saturated Interval 3 Negative vertical gradients are upward, positive gradients are downward 4 Wells denoted with "S" are shallow wells; wells denoted with "D" are deep wells APPENDIX A TEST BORING LOGS AND PIEZOMETER COMPLETION RECORDS Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840841.86 2293648.94 Located By: Northing: Easting: GS Elev.: 235.54 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description 235 230 225 220 215 210 205 200 0 5 10 15 20 25 30 35 3/27/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/27/13 Red Dog Drilling Strickland Land Surveying B. Boutin 58'-68' 237.46 54'-56' Locking Casing P-18D Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC 6-4-5-5 9-14-17-24 8-12-15-15 13-25-25-26 15-25-27-24 22-50/6 36-50/3 2.0 1.83 1.33 1.58 1.5 1.25 0.92 CL: Silty CLAY: some silt; sl. Plastic red-br to gr-br with depth. ML: Clayey SILT: little to some clay; sub-vertical foliations (appr. 1/8") appr. 60° become more distinct with depth; red-br-gr-tan; abundant weathered white mineral grains appr. 13'-15'; relict mineral filled fractures (<1/8") with rust colored filling beginning appr. 18'; horizontal partings (appr. 1/4")superimposed on sub-vertical foliations beginning appr. 23'. PWR-MA: Partially Weathered Rock: weathered meta-argillite; tr to little clay; subverical foliations varying from appr. 60° to 35-40° with depth; abundant dark weathered mineral grains; relict fractures beginning appr. 43' with br staining on fracture surfaces; abundant rock fragments; mostly gr. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840841.86 2293648.94 Located By: Northing: Easting: GS Elev.: 235.54 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description 195 190 185 180 175 170 165 160 40 45 50 55 60 65 70 75 3/27/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/27/13 Red Dog Drilling Strickland Land Surveying B. Boutin 58'-68' 237.46 54'-56' Locking Casing P-18D Notes: S-8 S-9 S-10 S-11 S-12 S-13 Bentonite Sand Screen 40-50/4 50/5 50/3 50/4 50/3 50/5 0.83 0.42 0.25 0.25 0.25 0.25 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840853.84 2293656.55 Located By: Northing: Easting: GS Elev.: 235.35 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description 235 230 225 220 215 210 205 200 0 5 10 15 20 25 30 35 3/28/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/27/13 Red Dog Drilling Strickland Land Surveying B. Boutin 30'-40' 237.36 26'-28' Locking Casing P-18S Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite Sand Screen 6-4-5-5 9-14-17-24 8-12-15-15 13-25-25-26 15-25-27-24 22-50/6 36-50/3 2.0 1.83 1.33 1.58 1.5 1.25 0.92 CL: Silty CLAY: some silt; sl. Plastic red-br to gr-br with depth. ML: Clayey SILT: little to some clay; sub-vertical foliations (appr. 1/8") appr. 60° become more distinct with depth; red-br-gr-tan; abundant weathered white mineral grains appr. 13'-15'; relict mineral filled fractures (<1/8") with rust colored filling beginning appr. 18'; horizontal partings (appr. 1/4")superimposed on sub-vertical foliations beginning appr. 23'. PWR-MA: Partially Weathered Rock: weathered meta-argillite; tr to little clay; subverical foliations varying from appr. 60° to 35-40° with depth; abundant dark weathered mineral grains; abundant rock fragments; mostly gr. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840853.84 2293656.55 Located By: Northing: Easting: GS Elev.: 235.35 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description 195 190 185 180 175 170 165 160 40 45 50 55 60 65 70 75 3/28/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/27/13 Red Dog Drilling Strickland Land Surveying B. Boutin 30'-40' 237.36 26'-28' Locking Casing P-18S Notes: S-8 40-50/4 0.83 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840490.69 2293872.91 Located By: Northing: Easting: GS Elev.: 227.93 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description 230 225 220 215 210 205 200 195 190 0 5 10 15 20 25 30 35 3/28/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/28/13 Red Dog Drilling Strickland Land Surveying B. Boutin 50'-60' 230.029 46'-48' Locking Casing P-19D Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC 5-8-14-17 16-22-25-25 14-20-32-32 16-19-21-21 10-12-14-14 14-22-31-43 33-50/4 1.17 1.0 1.5 1.25 1.67 2.0 0.83 CL: Silty CLAY: some silt; plastic; or-br. ML: Clayey SILT: little to some clay; sub-vertical foliations (appr. 1/8") appr. 50°-60° become more distinct with depth;tan-br-or; relict mineral filled fractures (<1/8") beginning appr. 8'; few rock fragments (meta-argillite); dark weathered mineral inclusions beginning appr. 18'; bl and rust or mineral stains along foliation and relict fracture plaes beginning appr. 28'. PWR-MA: Partially Weathered Rock: weathered meta-argillite; tr to little clay; sub-vertical foliations appr. 50°-60°; transitions from br to gr-or appr. 44.5'; abundant dark weathered mineral Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840490.69 2293872.91 Located By: Northing: Easting: GS Elev.: 227.93 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description190 185 180 175 170 165 160 155 150 40 45 50 55 60 65 70 75 3/28/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/28/13 Red Dog Drilling Strickland Land Surveying B. Boutin 50'-60' 230.029 46'-48' Locking Casing P-19D Notes: S-8 S-9 S-10 S-11 S-12 Bentonite Sand Screen 24-50/6 22-50/6 50/5 50/6 50/1 1.0 1.0 0.33 0.25 0.08 grains; abundant rock fragments; horizontal partings (appr. 1/8' to 1/4") superimposed on sub-vertical foliation beginning appr. 48'. PWR-PH: Partially Weathered Rock: weathered phyllite; emerald green; high chlorite content; wavy sub-vertical foliation (<1/8"); relict flow texture; abundant rock fragments; hard Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840498.14 2293868.68 Located By: Northing: Easting: GS Elev.: 228.23 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description 230 225 220 215 210 205 200 195 190 0 5 10 15 20 25 30 35 3/28/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/28/13 Red Dog Drilling Strickland Land Surveying B. Boutin 30'-40' 230.164 26'-28' Locking Casing P-19S Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite Sand Screen 5-8-14-17 16-22-25-25 14-20-32-32 16-19-21-21 10-12-14-14 14-22-31-43 33-50/4 1.17 1.0 1.5 1.25 1.67 2.0 0.83 CL: Silty CLAY: some silt; plastic; or-br. ML: Clayey SILT: little to some clay; sub-vertical foliations (appr. 1/8") appr. 50°-60° become more distinct with depth;tan-br-or; relict mineral filled fractures (<1/8") beginning appr. 8'; few rock fragments (meta-argillite); dark weathered mineral inclusions beginning appr. 18'; bl and rust or mineral stains along foliation and relict fracture plaes beginning appr. 28'. PWR-MA: Partially Weathered Rock: weathered meta-argillite; tr to little clay; sub-vertical foliations appr. 50°-60°; br; abundant dark weathered mineral grains; abundant rock fragments. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Date Started: Logged By: 840498.14 2293868.68 Located By: Northing: Easting: GS Elev.: 228.23 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description 190 185 180 175 170 165 160 155 150 40 45 50 55 60 65 70 75 3/28/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/28/13 Red Dog Drilling Strickland Land Surveying B. Boutin 30'-40' 230.164 26'-28' Locking Casing P-19S Notes: S-8 24-50/6 1.0 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841124.76 2294391.01 Located By: Northing: Easting: GS Elev.: 213.49 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 215 210 205 200 195 190 185 180 0 5 10 15 20 25 30 35 4/2/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/2/13 Red Dog Drilling Strickland Land Surveying B. Boutin 40'-50' 215.585 36'-38' Locking Casing P-20D Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite 21-21-27-29 15-11-18-19 6-12-13-11 6-7-10-11 4-8-12-15 6-5-7-12 10-13-17-22 1.0 0.83 1.25 1.5 1.5 1.83 1.17 ML: Clayey SILT: little to some clay; sl. plastic; various combinations of red-or- gr-br; sub-vertical foliations (appr. 1/8") varying from sub-horizontal to appr. 35°- 45° become more distinct with depth; relict mineral filled fractures (<1/8") beginning appr. 18' become more abundant with depth; few rock fragments (meta-argillite) up to appr. 1/8' dia.; weathered black mineral inclusions beginning appr. 38'; bl and rust or mineral stains along foliation and relict fracture planes. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841124.76 2294391.01 Located By: Northing: Easting: GS Elev.: 213.49 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 175 170 165 160 155 150 145 140 40 45 50 55 60 65 70 75 4/2/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/2/13 Red Dog Drilling Strickland Land Surveying B. Boutin 40'-50' 215.585 36'-38' Locking Casing P-20D Notes: S-8 S-9 S-10 Sand Screen 10-15-25-32 12-12-21-34 13-23-40-50/5 1.25 1.17 1.33 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841127.11 2294382.38 Located By: Northing: Easting: GS Elev.: 213.49 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 215 210 205 200 195 190 185 180 0 5 10 15 20 25 30 35 4/2/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/2/13 Red Dog Drilling Strickland Land Surveying B. Boutin 216.215 16'-18' Locking Casing P-20S Notes: S-1 S-2 S-3 S-4 S-5 S-6 Casing Sand Conc. Pad Grout 2" PVC Bentonite Sand Screen 21-21-27-29 15-11-18-19 UD Sample 6-7-10-11 4-8-12-15 6-5-7-12 1.0 0.83 1.25 1.5 1.5 1.83 ML: Clayey SILT: little to some clay; sl. plastic; various combinations of red-or- gr-br; sub-vertical foliations (appr. 1/8") varying from sub-horizontal to appr. 35°- 45° become more distinct with depth; relict mineral filled fractures (<1/8") beginning appr. 18' become more abundant with depth; few rock fragments (meta-argillite) up to appr. 1/8' dia.; weathered black mineral inclusions beginning appr. 38'; bl and rust or mineral stains along foliation and relict fracture planes. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841127.11 2294382.38 Located By: Northing: Easting: GS Elev.: 213.49 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 175 170 165 160 155 150 145 140 40 45 50 55 60 65 70 75 4/2/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/2/13 Red Dog Drilling Strickland Land Surveying B. Boutin 216.215 16'-18' Locking Casing P-20S Notes: Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841464.22 2294425.97 Located By: Northing: Easting: GS Elev.: 218.04 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 220 215 210 205 200 195 190 185 180 0 5 10 15 20 25 30 35 4/3/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/3/13 Red Dog Drilling Strickland Land Surveying S. Brey 220.171 46'-48' Locking Casing P-21D Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC 3-5-7-7 8-14-18-19 5-7-10-14 6-13-18-22 5-8-14-19 6-16-28-50/4 7-13-20-26 1.5 0.5 2.0 1.8 2.0 CL: Silty CLAY: little to some silt; low to medium plasticity; appr. 10-20% fine sand; organics appr. 8-10'; orange. ML: Clayey SILT: saprolite; relict rock texture and structure; sub-horizontal foliation appr. 20°; appr 15-20% fine sand; low to medium elasticity; variably or-red-gr-black-tan; rock fragments (meta-argillite) up to /4" dia. beginning appr. 38'; Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841464.22 2294425.97 Located By: Northing: Easting: GS Elev.: 218.04 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 180 175 170 165 160 155 150 145 140 40 45 50 55 60 65 70 75 4/3/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/3/13 Red Dog Drilling Strickland Land Surveying S. Brey 220.171 46'-48' Locking Casing P-21D Notes: S-8 S-9 S-10 S-11 S-12 Bentonite Sand Screen 15-22-28-31 12-50/5 50/4 50/4 50/5 1.8 0.8 0.33 0.33 0.5 PWR-MA: Partially Weathered Rock: weathered meta-argillite; abundant rock fragments; sub-horizontal foliation varying from appr. 10° to 30°; non- elastic; or-white. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841459.24 2294420.42 Located By: Northing: Easting: GS Elev.: 218.09 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 220 215 210 205 200 195 190 185 180 0 5 10 15 20 25 30 35 4/3/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/3/13 Red Dog Drilling Strickland Land Surveying S. Brey 219.899 26'-28' Locking Casing P-21D Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite Sand Screen 3-5-7-7 8-14-18-19 5-7-10-14 6-13-18-22 5-8-14-19 6-16-28-50/4 7-13-20-26 1.5 0.5 2.0 1.8 2.0 CL: Silty CLAY: little to some silt; low to medium plasticity; appr. 10-20% fine sand; organics appr. 8-10'; orange. ML: Clayey SILT: saprolite; relict rock texture and structure; sub-horizontal foliation appr. 20°; appr 15-20% fine sand; low to medium elasticity; variably or-red-gr-black-tan; rock fragments (meta-argillite) up to /4" dia. beginning appr. 38'; Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841459.24 2294420.42 Located By: Northing: Easting: GS Elev.: 218.09 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 180 175 170 165 160 155 150 145 140 40 45 50 55 60 65 70 75 4/3/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/3/13 Red Dog Drilling Strickland Land Surveying S. Brey 219.899 26'-28' Locking Casing P-21D Notes: S-8 15-22-28-31 1.8 PWR-MA: Partially Weathered Rock: weathered meta-argillite; abundant rock fragments; sub-horizontal foliation varying from appr. 10° to 30°; non- elastic; or-white. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841043.42 2293610.43 Located By: Northing: Easting: GS Elev.: 0 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 0 -5 -10 -15 -20 -25 -30 -35 0 5 10 15 20 25 30 35 3/26/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/26/13 Red Dog Drilling Strickland Land Surveying B. Boutin 40'-50' 238.616 36'-38' Locking Casing P-22 Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite 11-15-20-17 5-8-11-12 7-9-13-14 6-8-10-12 10-13-26-50/5 50/6 50/5 1.25 1.75 1.67 1.58 1.83 0.5 0.42 ML: Clayey SILT: little to some clay; relict rock texture; becomes more prominent with depth; visible sub- vertical foliation appr. 60-70° alt. red-or; abundant weathered dark mineral grains; relict sub-vertical fractures beginning appr. 18 ft. PWR-MA: Partially Weathered Rock: weathered meta-argillite; slaty texture; abundant rock fragments; sub-vertical foliation (appr. 60-70°) varying from lt br-gr-tan to alt gr-red with depth; sub- vertical fractures with black staining on fracture surfaces;. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841043.42 2293610.43 Located By: Northing: Easting: GS Elev.: 0 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: -40 -45 -50 -55 -60 -65 -70 -75 40 45 50 55 60 65 70 75 3/26/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/26/13 Red Dog Drilling Strickland Land Surveying B. Boutin 40'-50' 238.616 36'-38' Locking Casing P-22 Notes: S-8 S-9 S-10 Sand Screen 31-50/4 50/5 50/4 0.33 0.42 0.33 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 840883.75 2293361.32 Located By: Northing: Easting: GS Elev.: 236.61 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 1 Boring Well DiagramPr o f i l e Description Date Started: 235 230 225 220 215 210 205 200 0 5 10 15 20 25 30 35 3/27/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/27/13 Red Dog Drilling Strickland Land Surveying B. Boutin 28'-38' 240.381 24'-26' Locking Casing P-23 Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite Sand Screen 50/5 50/5 12-25-37-50/5 50/5 50/4 50/2 50/2 0.42 0.42 1.17 0.42 0.33 0.17 0.17 PWR-MA: Partially Weathered Rock: weatherd meta-argillite; abundant rock fragments beginning appr. 18'; sub- vertical foliation (appr. 60-70°) with thin (<1/8") laminae varying from red-br-or- tan to alt gr-br-tan with depth; black staining on foliation surfaces; horizontal laminae (appr. 1/4") beginning appr. 13'; hard; wet, saturated at appr. 33;. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 840763.07 2294163.72 Located By: Northing: Easting: GS Elev.: 229.94 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 230 225 220 215 210 205 200 195 0 5 10 15 20 25 30 35 4/1/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/1/13 Red Dog Drilling Strickland Land Surveying B. Boutin 45'-55' 232.15 41'-43' Locking Casing P-24 Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC 6-7-14-16 13-15-23-29 17-27-38-50/5 25-50/6 25-50/5 22-41-50/4 21-44-50/4 1.17 1.42 1.17 0.83 0.83 1.33 1.33 CL: Silty CLAY: some silt; plastic; red- br. ML: Clayey SILT: little to some clay; sub-vertical foliations (appr. 1/8") appr. 70° become more distinct with depth; alt. gr-or-red-br with gr predominant; relict mineral filled fractures (<1/8") beginning appr. 13'; few rock fragments (meta-argillite); dark weathered mineral inclusions beginning appr. 13'; bl and rust or mineral stains along foliation and relict fracture planes; horizontal partings (appr. 1/4"-1/2") superimposed on sub-vertical foliation beginning appr. 10'. PWR-MA: Partially Weathered Rock: weathered meta-argillite; tr to little clay; subverical foliations appr. 50°-70°; or- red-gr-br; abundant dark weathered mineral grains; abundant rock fragments; horizontal partings (appr. 1/4"-1/2") superimposed on sub-vertical foliation; relict mineral filled fractures; black to rust or stains along foliation and relict fracture planes; alt. hard and softer zones beginning appr. 21'. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 840763.07 2294163.72 Located By: Northing: Easting: GS Elev.: 229.94 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 190 185 180 175 170 165 160 155 40 45 50 55 60 65 70 75 4/1/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/1/13 Red Dog Drilling Strickland Land Surveying B. Boutin 45'-55' 232.15 41'-43' Locking Casing P-24 Notes: S-8 S-9 S-10 S-11 Bentonite Sand Screen 31-37-50/5 25-50/4 50/6 50/6 1.42 0.67 0.42 0.5 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 840599.53 2294412.15 Located By: Northing: Easting: GS Elev.: 227.52 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 230 225 220 215 210 205 200 195 190 0 5 10 15 20 25 30 35 4/2/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/1/13 Red Dog Drilling Strickland Land Surveying B. Boutin 50'-60' 229.289 46'-48' Locking Casing P-25 Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC 8-12-19-22 6-8-11-14 7-12-15-23 10-12-18-23 10-25-50/6 32-50/5 50/3 1.0 1.5 1.25 1.58 1.42 0.92 0.25 CL: Silty CLAY: some silt; plastic; red- br. ML: Clayey SILT: little to some clay; sub-vertical foliations (appr. 1/8") appr. 50°-60° become more distinct with depth; alt. gr-or-red-tan-br becomes mostly gr with or laminae at appr. 23'; relict mineral filled fractures (<1/8") beginning appr. 8'; few rock fragments (meta-argillite); bl and rust or mineral stains along foliation and relict fracture planes; horizontal partings (appr. 1/4"- 1/2") superimposed on sub-vertical foliation beginning appr. 18'. PWR-MA: Partially Weathered Rock: weathered meta-argillite; tr to little clay; subverical foliations appr. 50°-70°; gr- or-tan with gr predominant; abundant rock fragments up to 1" dia.; horizontal partings (appr. 1/4"-1/2") superimposed on sub-vertical foliation; relict mineral filled fractures; black to rust or stains along foliation and relict fracture planes; alt. hard and softer zones beginning appr. 35';. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 840599.53 2294412.15 Located By: Northing: Easting: GS Elev.: 227.52 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 185 180 175 170 165 160 155 150 40 45 50 55 60 65 70 75 4/2/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 4/1/13 Red Dog Drilling Strickland Land Surveying B. Boutin 50'-60' 229.289 46'-48' Locking Casing P-25 Notes: S-8 S-9 S-10 S-11 Bentonite Sand Screen 50/3 50/4 50/3 50/3 0.25 0.25 0.25 0.25 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841066.33 2294084.21 Located By: Northing: Easting: GS Elev.: 235.06 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 235 230 225 220 215 210 205 200 0 5 10 15 20 25 30 35 3/25/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/25/13 Red Dog Drilling Strickland Land Surveying B. Boutin 35'-45' 237.361 31'-33' Locking Casing P-26 Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite 5-5-9-14 39-50/5 39-50/3 30-50/4 42-50/3 40-50/6 50/6 1.5 .75 .67 .67 .75 .75 .5 CL: Silty CLAY: little to some silt; plastic; red-br. ML: Clayey SILT: little to some clay; faint relict rock texture; visible relict sub- vertical foliation appr. 1/8" to1/4" thick; red-br. PWR-MA: Partially Weathered Rock: weathered meta-argillite ( clayey silt); rock fragments (meta-argillite) up to 1/2"; dark staining along foliation planes below appr. 18 ft.; thin horizontal laminations superimposed on sub- vetical foliation planes beginning appr. 23 ft.; red-or-br-tan-gray; hard drilling beginning at appr. 37 ft; variably colored red-br-tan-or-gray. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841066.33 2294084.21 Located By: Northing: Easting: GS Elev.: 235.06 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 195 190 185 180 175 170 165 160 40 45 50 55 60 65 70 75 3/25/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/25/13 Red Dog Drilling Strickland Land Surveying B. Boutin 35'-45' 237.361 31'-33' Locking Casing P-26 Notes: S-8 S-9 Sand Screen 50/5 20-31-50/5 .333 .58 Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841347.82 2294688.18 Located By: Northing: Easting: GS Elev.: 200.38 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 1 Boring Well DiagramPr o f i l e Description Date Started: 200 195 190 185 180 175 170 165 0 5 10 15 20 25 30 35 3/26/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/26/13 Red Dog Drilling Strickland Land Surveying B. Boutin 20'-30' 202.199 16'-18' Locking Casing P-27 Notes: S-1 S-2 S-3 S-4 S-5 S-6 Casing Sand Conc. Pad Grout 2" PVC Bentonite Sand Screen 7-9-15-23 7-11-12-15 5-9-12-15 7-13-20-32 7-9-15-18 29-18-18-25 1.58 1.67 2.0 1.67 2.0 2.0 CL: Silty CLAY: some silt; plastic; dk br to br. ML: Clayey SILT: little to some clay; relict rock texture; becomes more prominent with depth; visible sub- vertical foliation appr. 60° alt. red-br-or- yel to red-br-gr and br-tan-gr with depth; weathered dark mineral grains; thin horizontal laminations superimposed on sub-vetical foliation planes beginning appr. 13 ft; wet zone 23'-24'; hard drilling appr. 27-29.5 ft with rock fragments (meta-argillite) up to appr. 0.5"; lt br-gr-tan at end of section. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841695.1 2294398.756 Located By: Northing: Easting: GS Elev.: 223.92 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page1 of 2 Boring Well DiagramPr o f i l e Description Date Started: 225 220 215 210 205 200 195 190 0 5 10 15 20 25 30 35 3/26/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/26/13 Red Dog Drilling Strickland Land Surveying B. Boutin 35'-45' 226.193 31'-33' Locking Casing P-28 Notes: S-1 S-2 S-3 S-4 S-5 S-6 S-7 Casing Sand Conc. Pad Grout 2" PVC Bentonite 5-5-8-10 5-8-13-15 22-25-30-31 22-34-41-50/5 26-27-35-44 17-22-28-30 9-11-19-29 0.67 1.0 1.5 1.67 1.33 1.67 2.0 CL: Silty CLAY: some silt; loose; or-br. ML: Clayey SILT: little to some clay; relict rock texture; visible sub-vertical foliation appr. 60 to 70° alt. or-gr; weathered dark mineral grains; dark staining along foliation planes below appr. 18 ft.; thin horizontal laminations superimposed on sub-vetical foliation planes beginning appr. 8 ft. with dark staning along planes at depth; variably colored red-or-br-bl-tan-gray; hard drilling beginning at appr. 41.5 ft. Sa m p l e Per (0.5') SPT Date Completed: Drilling Method: Sampling Method: Re c . ( f t ) Blows Nu m b e r Sa m p l e De p t h ( f t ) El e v . Drilling Company: Logged By: 841695.1 2294398.756 Located By: Northing: Easting: GS Elev.: 223.92 Well Construction Record ToC Elev.: Screen Int. (ft, BGS): Seal (ft, BGS): Completion: Page2 of 2 Boring Well DiagramPr o f i l e Description Date Started: 185 180 175 170 165 160 155 150 40 45 50 55 60 65 70 75 3/26/13 Hollow Stem Auger SPT/Split Spoon Nash County C&D Landfill Expansion Design Hydrogeologic Investigation 3/26/13 Red Dog Drilling Strickland Land Surveying B. Boutin 35'-45' 226.193 31'-33' Locking Casing P-28 Notes: S-8 S-9 Sand Screen 12-17-21-30 50/3 2.0 0.25 PWR-MA: Partially Weathered Rock: brittle with mostly gray laminations with interspersed orange layers; abundant rock fragments (weathered meta- argillite); hard. APPENDIX B GEOTECHNICAL LABORATORY DATA APPENDIX C SLUG TEST RESULTS GAS CONTROL PLAN Horizontal Expansion of the Nash County C&D Landfill October 2016 1100 Crescent Green Drive, Suite 208 Cary, North Carolina 27518 • O: 919-792-1900 • F: 866-311-7206 This page intentionally left blank GAS CONTROL PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL i TABLE OF CONTENTS TABLE OF CONTENTS ................................................................................................... I GAS CONTROL PLAN ......................................................................................... 1 ROUTINE MONITORING PLAN ........................................................................... 1 EXPLOSIVE GAS CONCENTRATION LIMITS .................................................... 1 FIELD MEASUREMENT PROTOCOL .................................................................. 2 REPORTING ......................................................................................................... 3 CORRECTIVE ACTIONS ...................................................................................... 3 APPENDIX A – LFG MONITORING FORM TABLE 1 - LFG PROBE ID AND COORDINATES FIGURE 1 – LFG PROBE LOCATIONS GAS CONTROL PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 1 of 3 GAS CONTROL PLAN Rule 15A NCAC 13B .0544 (d) requires a gas control plan that ensures: (A) The concentration of methane gas or other explosive gases generated by the facility does not exceed 25 percent of the lower explosive limit (LEL) in on-site facility structures (excluding gas control or recovery system components). (B) The concentration of methane gas or other explosive gases does not exceed the lower explosive limit for methane or other explosive gases at the facility property boundary; and (C) The facility does not release methane gas or other explosive gases in any concentration that can be detected in offsite structures. Routine Monitoring Plan Rule 15A NCAC 13B .0544 (d)(2) requires owners and operators of C&DLF units to implement a routine gas control monitoring program to ensure that the explosive gas concentration standards are met. Table 1 shows the coordinates of landfill gas monitoring wells associated with Horizontal Expansion of the Nash County C&D Landfill. Figure 1 shows the locations of landfill gas monitoring wells associated with Horizontal Expansion of the Nash County C&D Landfill. The landfill gas monitoring wells are located based on soil conditions, the hydrogeologic conditions under and surrounding the facility, hydraulic conditions on and surrounding the facility, the location of facility structures and property boundaries, and the location of all off-site structures adjacent to property boundaries. The landfill gas monitoring wells shall be monitored quarterly. Explosive Gas Concentration Limits The operator shall ensure that the concentration of explosive gases generated by the facility does not exceed 25% of the corresponding lower explosive limit (LEL) in on-site facility structures. Further, the operator of the C&D landfill shall ensure that the concentration of explosive gases does not exceed 100% of the corresponding LEL at the facility property boundary. GAS CONTROL PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 2 of 3 Rule 15A NCAC 13B .0544 (d)(5) defines “lower explosive limit” as “the lowest percent by volume of a mixture of explosive gases in air that will propagate a flame at 25°C and atmospheric pressure”. The explosive gases typically associated with C&D landfills, and the corresponding LEL at the stated conditions are as follows: Explosive Gas Lower Explosive Limit (LEL) On-site Facility Structures Facility Property Boundary Methane 5% 25% LEL 100% LEL Hydrogen Sulfide 4% 25% LEL 100% LEL Field Measurement Protocol A landfill gas monitoring unit capable of measuring methane and hydrogen sulfide concentrations as a percent of total atmospheric gases shall be used to measure explosive gas concentrations at each of the existing gas control probe locations and facility structures. Corresponding values of the percent of atmospheric carbon dioxide and the percent of atmospheric oxygen will likewise be documented. No laboratory sampling or analysis will be conducted under this plan. Landfill Gas Analyzer Calibration Calibration of the landfill gas analyzer is critical to obtaining accurate sampling results. Immediately prior to conducting field measurements, the landfill gas analyzer will be calibrated according to the manufacturer’s recommendations in an area expected to be free of. Calibration of the unit should be performed immediately prior to beginning routine monitoring, and in no case greater than 12 hours before sampling. Occupied Structures Readings Permanent structures are constructed on a concrete slab-on-grade or elevated on a crawlspace. Structures containing a crawlspace or otherwise open area between the structure and ground surface will be monitored. Reading for occupied structures with a slab-on-grade will be made inside the structures with the landfill gas analyzer’s probe as high from the floor as practical. Readings will be recorded when the gas analyzer has reached equilibrium and the readout has stabilized. GAS CONTROL PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 3 of 3 Gas Probe Readings The pump within the landfill gas analyzer is sized to allow the meter to rapidly purge the typical probe casing. Readings for the existing landfill gas probes will be made by first connecting the analyzer probe to the well casing with the shutoff valve in the open position. Positive connection of the probe to the quick-connect attachment should be checked to see that the opportunity for ambient air to be drawn into the analyzer is minimized. Readings will be recorded when the analyzer has reached equilibrium and the readout has stabilized. Reporting Quarterly gas control monitoring results shall be submitted to NCDENR on the form attached at the end of this Plan. Corrective Actions Rule 15A NCAC 13B .0544 (d)(5) specifies the corrective action requirements if methane gas levels exceeding the limits specified in Subparagraph (d)(1) are detected. 1) Immediately take all necessary steps to ensure protection of human health and notify the Division. 2) Within seven (7) days of detection, place in the operating record a copy of the explosive gas levels detected and a description of the steps taken to protect human health; and 3) Within sixty (60) days of detection, implement a remediation plan for the explosive gas release, place a copy of the plan in the operating record, and notify the Division that the plan has been implemented. The plan shall describe the nature and extent of the problem, the proposed remedy. Table 1 Landfill Gas Probes Gas Probe ID Northing Easting MM-1 840,932.81 2,293,132.45 MM-2 841,284.69 2,293,314.10 MM-3 841,628.74 2,293,394.58 MM-4 841,877.22 2,293,531.39 MM-5 841,931.54 2,293,902.60 MM-6 841,789.70 2,294,152.09 MM-7 841,606.61 2,294,508.21 MM-8 841,210.04 2,294,718.94 MM-9 840,863.38 2,294,514.55 MM-10 840,434.32 2,294,234.85 MM-11 840,523.13 2,293,856.34 MM-12 840,644.88 2,293,493.26 APPENDIX A LFG MONITORING FORM   16    NC Division of Waste Management - Solid Waste Section Landfill Gas Monitoring Data Form Notice: This form and any information attached to it are "Public Records" as defined in NC General Statute 132-1. As such, these documents are available for inspection and examination by any person upon request (NC General Statute 132-6). Facility Name: ______________________________________________ Permit Number: ____________________________ Date of Sampling: ___________________ NC Landfill Rule (.0500 or .1600): _____________________________________ Name and Position of Sample Collector: _________________________________________ Type and Serial Number of Gas Meter: _______________________________ Calibration Date of Gas Meter: ___________ Date and Time of Field Calibration: _____________________ Type of Field Calibration Gas (15/15 or 35/50): ____________ Expiration Date of Field Calibration Gas Canister: ________ Pump Rate of Gas Meter: _____________ Ambient Air Temperature: __________ Barometric Pressure: ______________ General Weather Conditions: _____________ Instructions: Under “Location or LFG Well” identify the monitoring wells or describe the location for other tests (e.g., inside buildings). A drawing showing the location of test must be attached. Report methane readings in both % LEL and % methane by volume. A reading in percent methane by volume can be converted to % LEL as follows: % methane by volume = % LEL/20 If your facility has more gas monitoring locations than there is room on this form, please attach additional sheets listing the same information as contained on this form. Certification To the best of my knowledge, the information reported and statements made on this data submittal and attachments are true and correct. I am aware that there are significant penalties for making any false statement, representation, or certification including the possibility of a fine and imprisonment. _________________________________________ _________________________________________ SIGNATURE TITLE Groundwater and Surface Water Monitoring Plan Nash County C&D Landfill And Horizontal Expansion October 2016 1100 Crescent Green Drive, Suite 208 Cary, North Carolina 27518 • O: 919-792-1900 • F: 866-311-7206 This page intentionally left blank GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL i CONTENTS 1.0 INTRODUCTION ....................................................................................................... 1 2.0 GROUNDWATER AND SURFACE WATER SAMPLING LOCATIONS .................... 1 2.1 STATIC WATER LEVEL MEASUREMENTS ......................................................... 2 2.2 DETECTION OF IMMISCIBLE LIQUIDS ............................................................... 2 2.3 MONITORING WELL PURGING ........................................................................... 3 2.4 GROUNDWATER SAMPLE COLLECTION .......................................................... 3 2.5 SURFACE WATER SAMPLE COLLECTION ........................................................ 4 2.6 EQUIPMENT DECONTAMINATION ..................................................................... 5 2.7 FIELD QA/QC PROGRAM .................................................................................... 5 3.0 SAMPLE PRESERVATION AND SHIPMENT ........................................................... 5 4.0 FIELD LOGBOOK ..................................................................................................... 6 5.0 LABORATORY ANALYSIS ....................................................................................... 7 6.0 STATISTICAL EVALUATION .................................................................................... 7 7.0 RECORD KEEPING AND REPORTING ................................................................... 8 7.1 NOTIFICATIONS ................................................................................................... 8 7.2 WELL ABANDONMENT/REHABILITATION .......................................................... 9 7.3 IMPLEMENTATION SCHEDULE .......................................................................... 9 Figure 1 – Monitoring Locations Table 1 – Monitoring Location Data Table 2 - Laboratory Analytical Testing Parameters for Surface Water and Groundwater Samples This page intentionally left blank GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 1 of 11 1.0 INTRODUCTION The North Carolina Solid Waste Rules, Section 13B .0504, specifies that the owner/operator must provide, as part of the groundwater and surface water monitoring program, a water quality sampling and analysis plan (SAP). The SAP is to be designed to provide accurate assessment of groundwater and surface water quality at upgradient/upstream and downgradient/downstream sampling locations. This SAP addresses the following subjects. • Groundwater and surface water sample collection • Sample preservation and shipment • Analytical procedures • Chain-of-custody • Quality assurance/quality control (QA/QC) The methods and procedures described in the following sections are intended to provide representative samples and test data. Field procedures are presented in their general order of implementation. Equipment requirements are presented in each section, and quality assurance and record keeping requirements are presented in the last sections. Strict adherence to these procedures is required. 2.0 GROUNDWATER AND SURFACE WATER SAMPLING LOCATIONS Groundwater and surface water will be monitored at locations as shown on Figure 1. Well construction data for the groundwater well network is presented in Table 1. Table 1 further indicates the timing of well installation and/or abandonment relative to the phase of landfill operation. Groundwater and surface water samples will be collected from each monitoring point and analyzed for a list of detection monitoring target parameters in accordance with NC Division of Waste Management (NC DWM) regulations. Baseline detection monitoring will consist of four independent sampling events during the initial semi-annual period, followed by semi-annual sampling at each location thereafter. The detection monitoring wells are designed to monitor the shallow aquifer at the site and are constructed of 2-inch inside diameter Schedule 40 PVC, with isolated well screen intervals, in accordance with North Carolina well construction standards 15A NCAC 2C. GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 2 of 11 2.1 STATIC WATER LEVEL MEASUREMENTS Static water levels will be measured in each monitoring well prior to purging and sampling of groundwater. Static water level data will be used to monitor changes in site hydrogeologic conditions. The following measurements will be recorded in a dedicated field book prior to purging and sample collection. • Static water level (measured to nearest 0.01 foot) • Total depth of well • Height of water column in well • Changes in conditions of well, protective casing, surface pad and surroundings An electronic water level instrument will be used to accurately measure water levels to within 0.01 foot. Each well will have a permanent, easily identified reference point on the top of the PVC well casing from which all water level measurements will be made. The reference point will be marked and the elevation of the top of the PVC casing will surveyed by a North Carolina Registered Land Surveyor. The static water level and total depth measurements will be used to calculate the volume of water in the well. The parts of the static water level instrument that will contact groundwater within the well (e.g., graduated tape and electronic indicator) will be constructed of inert materials such as stainless steel and Teflon™. The instrument will be thoroughly decontaminated between well measurements by washing with non-phosphate soap and triple rinsing with deionized water to prevent cross-contamination from one well to another. 2.2 DETECTION OF IMMISCIBLE LIQUIDS The detection of immiscible non-aqueous phase liquids (NAPLs) is not anticipated at this facility based on the waste stream handled. However, the water-level measuring instrument used at the facility (described above) will be equipped with an electronic interface probe that is capable of distinguishing NAPLs from water. Monitoring for both light NAPLS (less dense than water) and dense NAPLs (more dense than water) will be conducted at the site by measuring at the water-table and at the bottom of each well. In the event that NAPLs are detected, the instrument will initially be cleaned with denatured laboratory grade isopropyl alcohol, followed by washing with non-phosphate soap and triple rinsing with deionized water to prevent cross-contamination from one well to another. GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 3 of 11 2.3 MONITORING WELL PURGING Following measurement of the static water levels in all of the wells, individual wells will be purged of all stagnant water. The stagnant water, which is not representative of true aquifer conditions, must be removed to ensure that fresh formation water can be sampled. Each monitoring well will be purged using a new PVC disposable bottom-loading bailer or using pre-cleaned Teflon-lined disposable polyethylene tubing connected to a peristaltic pump under low flow conditions. Prior to sampling, the monitoring wells will be purged of a minimum of three static well volumes of water, or until dry. During purging, measurements will be made in the field of the pH, temperature, specific conductance and turbidity of the groundwater collected from the monitoring wells, in accordance with NC DWM requirements. Data collected will be recorded in a dedicated field book. 2.4 GROUNDWATER SAMPLE COLLECTION After the wells are purged, groundwater samples will be collected for laboratory analysis. New latex or nitrile disposable gloves will be donned prior to sampling at each well. Groundwater samples will be collected using the new disposable PVC bottom-loading bailers that were used to purge the wells or using the pre-cleaned Teflon-lined disposable polyethylene tubing connected to a peristaltic pump under low flow conditions. In general, sampling will be conducted as soon as practical after purging is complete. In the event that a monitoring well runs dry during purging, it is acceptable to allow the well to recharge up to 24 hours prior to sampling. Similarly, wells with excess turbidity may be allowed to sit up to 24 hours prior to sampling to allow collection of a representative groundwater sample. Water levels in the wells will be allowed to recover for a period not exceeding 24 hours after purging to produce an adequate sample volume. Wells that fail to produce an adequate sample volume within 24 hours of purging will not be sampled. Temperature, ph, specific conductance and turbidity will be measured immediately prior to sampling as a measure of purging efficiency and the results recorded in a dedicated field book. The temperature, pH, specific conductance and turbidity meters will be calibrated prior to each sampling event according to the manufacturer’s specifications and consistent with Test Methods for Evaluating Solid Waste – Physical/Chemical Methods (SW-846). Groundwater samples will be collected and contained in the order of volatility of specific parameters as follows. • Temperature, ph, specific conductance and turbidity measurements • Volatile Organic Compounds GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 4 of 11 • Total Metals All detection monitoring samples will be collected unfiltered as required by the NC DWM. All reusable sampling equipment, including meter probes, will be thoroughly decontaminated between wells by washing with non-phosphate soap and water, followed by triple rinsing with deionized water. Samples will be collected directly from the disposable bailers or the Teflon-lined disposable polyethylene tubing connected to the peristaltic pump into laboratory-prepared containers that have been specifically prepared for the preservation and storage of compatible parameters. All groundwater sample containers will be immediately placed on ice in a cooler following sample collection in accordance with required sampling protocol. Blanks and duplicate samples will be collected and analyzed for the same parameters as groundwater samples to ensure cross-contamination has not occurred. One set of trip blanks, described later in this document, will be prepared at the laboratory and will remain in the sample cooler during sample collection and shipment to the laboratory for analysis to ensure that the sample containers or handling processes have not affected the quality of the samples. A duplicate groundwater sample may be collected from a single well as a check of laboratory accuracy and reproducibility. 2.5 SURFACE WATER SAMPLE COLLECTION Surface water samples will be obtained from areas of minimal turbulence and aeration. The following procedure will be implemented for sampling surface water at each location. • Don new latex or nitrile disposable gloves • Hold sample bottle with one hand, and with the other, remove the cap • Push the sample container slowly into the water column and tilt up towards the current to fill. A depth of about 6 inches is satisfactory. Avoid breaching the surface or agitating the water while filling the container • If there is little current movement, the container should be moved slowly in a lateral direction, side to side, keeping the opening pointed upstream. Blanks and duplicates, preservatives, handling and transport procedures for the surface water samples will be identical to those noted form the groundwater samples. GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 5 of 11 2.6 EQUIPMENT DECONTAMINATION All non-dedicated sampling equipment that will come into contact with groundwater or surface water will be decontaminated before each use. The equipment decontamination procedure is presented below. • Clean item with tap water and non-phosphate detergent (Alconox™, Liquinox™ or equivalent), using a brush if necessary to remove particulate matter and surface films • Rinse thoroughly with tap water • Triple rinse with deionized water and allow to air dry • Wrap with aluminum foil, if necessary, to prevent contamination of equipment during storage or transport 2.7 FIELD QA/QC PROGRAM Field Quality Assurance/Quality Control (QA/QC) for the subject facility requires the routine collection and analysis of trip blanks to verify that the sampling collection and handling process has not affected the quality of the samples. The trip blanks will be prepared at the laboratory and transported to the site in the sample cooler with the field sample containers, handled like a sample collected in the field, and returned to the laboratory for analysis. The trip blanks will be analyzed for volatile organic compounds (VOCs) only. Any VOCs found in the trip blanks will be attributed to: 1) contaminated sample container in which the blank was prepared; 2) contaminated source water; or 3) contamination during handling. Any concentrations of contaminants found in the trip blanks will be reported but will not be used to correct the water-quality data for the groundwater or surface water samples. In the event that elevated constituent concentrations are found in the trip blanks, the laboratory results for that constituent in the field samples will be flagged for future evaluation and possible resampling. 3.0 SAMPLE PRESERVATION AND SHIPMENT Sample preservation and shipment procedures will be carefully monitored to ensure sample integrity. Ice and/or chemical ice packs will be used to preserve samples in a cooler at the required 4°C temperature. Dry ice is not to be used. Samples will be delivered to the laboratory via overnight courier to ensure sample holding times are not exceeded. Shipment and receipt of the samples will be coordinated with the laboratory. Once collected, samples will be placed on ice and cooled to a temperature of 4°C. Samples are to be packed in high-impact polystyrene-insulated coolers so as to inhibit GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 6 of 11 breakage of sample containers. Chain-of-custody control of all samples will be maintained as follows. • Labels will be placed on individual sample containers in the field, indicating the site name, sample location, time and date of sampling, required analyses, sampler’s initials and sample preservative. • Sample containers will be individually secured or placed in a secure area in iced coolers and will remain in the continuous possession of the field samplers until custody has been transferred as provided by the chain-of- custody form. • Upon delivery to the laboratory, samples will be given laboratory sample numbers and recorded into a logbook indicating client, well number, and date and time of delivery. The laboratory manager or his designee will sign the chain-of-custody forms and formally receive the samples. Proper refrigeration of the samples will be maintained at the laboratory prior to preparation of the 4.0 FIELD LOGBOOK The field samplers will maintain an up-to-date logbook and sampling forms documenting important information pertaining to field sampling activities. The field logbook and sampling forms will document the following. • Site name and location • Date and time of sampling • Climatic conditions at the time of sampling • Personnel conducting the sampling • Sampling locations • Presence of NAPLs • Static water levels in wells • Total depth of wells • Purged water volumes and qualitative well yield • Time well purged • Observations of water samples (appearance, odor, etc.) • Time of sample collection GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 7 of 11 • Temperature, pH, specific conductance and turbidity 5.0 LABORATORY ANALYSIS The groundwater and surface water parameters to be analyzed will be those specified in the landfill permit and applicable North Carolina Solid Waste Management Rules. These will include field indicators of groundwater quality (temperature, pH, specific conductivity and turbidity), as well as volatile organic and total metal constituents listed in Appendix I of 40 CFR 258. All laboratory analyses will be performed by a laboratory certified by the NC DWM for the analyzed parameters. QA/QC procedures are to be utilized at all times. The owner/operator of the landfill is responsible for selecting a laboratory and ensuring that they are utilizing proper QA/QC procedures. The laboratory must have a QA/QC program based on specific routine procedures outlined in a written laboratory QA/QC manual. The QA/QC procedures listed in the manual provide the laboratory with the necessary assurances and documentation for accuracy and precision of analytical determinations. Internal QC checks shall be undertaken regularly by the laboratory to assess the precision and accuracy of analytical procedures. The internal QC checks include the use of calibration standards, standard references, duplicate samples and spiked or fortified samples. Calibration standards shall be verified against a standard reference obtained from an outside source. Calibration curves shall be developed using at least one blank and three standards. Samples shall be diluted if necessary to ensure that analytical measurements fall on the linear portion of the calibration curve. Duplicate samples shall be processed at an average frequency of 10 percent to assess the precision of testing methods, and standard references shall be processed monthly to assess accuracy of analytical procedures. Spike or fortified samples shall be carried through all stages of sample preparation and measurement to validate the accuracy of the analysis. During the course of analyses, QC data and sample data shall be reviewed by the laboratory manager to identify questionable data and determine if the necessary QA/QC requirements are being followed. If a portion of the laboratory work is subcontracted, it is the responsibility of the contracted laboratory to verify that all subcontracted work is completed by certified laboratories. 6.0 STATISTICAL EVALUATION Copies of all laboratory results and water quality reports will be kept in the Operation Record. Reports summarizing all water quality data and statistical evaluations will be submitted to the NC DWM for each sampling event following the baseline monitoring period. Methods to evaluate the data are taken from the North Carolina Solid Waste GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 8 of 11 Rules, 40 CFR 258.53(g) and the USEPA RCRA Ground Water Monitoring Technical Guidance. The North Carolina Solid Waste Rules require that the owner or operator of the landfill specify a statistical method outlined in the rules to evaluate water quality monitoring data. The goal of the statistical analysis is to determine whether statistically significant evidence of contamination exists and to identify the point of contamination. Upon receipt of the data from each monitoring event, the statistical database of analyses will be updated. The North Carolina Solid Waste Rules provide several acceptable methods for statistical analysis of water-quality data. • Parametric analysis of variance (ANOVA) • Rank-based (non-parametric) ANOVA with multiple comparisons • Tolerance prediction interval • Control chart • Test of proportions • An alternative statistical method that meets the performance standards of 40 CFR 258.53(h) Statistical evaluation of water-quality monitoring data will be performed for the duration of the monitoring program, including the post-closure care period. The choice of an appropriate statistical test depends on the type of monitoring, the nature of the data, and the proportion of values in the data set that are below detection limits. The statistical analysis will be performed separately for each detected constituent in each well. The statistical methods used will be based on the USEPA Statistical Analysis of Ground Water Monitoring Data at RCRA Facilities, Interim Final Guidance Document (1989). All analyses will be performed in accordance with North Carolina Regulations 15A NCAC 13B.1632. 7.0 RECORD KEEPING AND REPORTING 7.1 NOTIFICATIONS Should a statistically significant increase in groundwater concentrations of monitored parameters as defined in the North Carolina Solid Waste Rules be detected during monitoring, the owner/operator of the landfill shall notify the NC DWM within 14 days and will place a notice in the operating record as to which constituents showed an increase. GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 9 of 11 7.2 WELL ABANDONMENT/REHABILITATION Should monitoring wells become irreversibly damaged or require rehabilitation, the NC DWM shall be notified. If monitoring wells and/or piezometers are damaged irreversibly they shall be abandoned under the direction of the NC DWM. The abandonment will consist of plugging the well with a chemically inert sealant which is impermeable, such as neat cement and/or bentonite clay. Where possible, it is preferred to over-drill and remove the well casing, screen and filter pack prior to grouting. 7.3 IMPLEMENTATION SCHEDULE This Water Quality SAP shall become effective upon approval by the NC DWM and will be implemented contingent on approval for construction of the landfill expansion. Baseline sampling shall commence as soon as possible after the expansion phase is granted approval and prior to waste being disposed each the new phase. Four independent rounds of sampling and laboratory analyses of groundwater and surface water shall be performed within six months of approval of the landfill expansion. Sampling will then be performed semi-annually throughout the active life of operational life of the facility and during the post-closure monitoring period, unless an alternate sampling schedule is accepted by the NC DWM. Table 1 presents timing of well installation and/or abandonment relative to the phase of landfill operation. Proposed locations and anticipated screen intervals are shown on Figure 1. Table 1 – Installation and Abandonment Schedule Phase Install Abandon Notes 4 MW-6R*; MW-7 MW-6; P-20S; P- 20D *Rename existing P-21S to MW- 6R; 5 MW-8 P-26 6 None P-24, P-25 7 MW-9* None *Rename existing P-19S to MW- 9 8 None P-22 9 None P-23 Installation and abandonment procedures are discussed in detail in Section 8. GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 10 of 11 8.0 WELL CONSTRUCTION AND DECOMMISSIONING SPECIFICATIONS Table 1 presents timing of well installation and/or abandonment relative to each phase of landfill operation. The following subsections describe construction and abandonment specifications. 8.1 CONSTRUCTION SPECIFICATIONS The proposed Type II groundwater monitoring wells will be installed using a hollow- stem auger drilling rig. All Type II wells will be constructed of 2-inch ID Schedule 40 PVC well casing and 10 feet of machine-slotted well screen with 0.010” slots. A sand pack will be emplaced within the annular space to approximately 2 feet above the top of the well screen, above which a 2-foot thick bentonite seal will be installed. The annular space will be finished with Portland cement/bentonite slurry to grade. The wells will be finished with solid PVC risers extending approximately 2 to 3 feet above grade and installed in a locking steel casing with concrete pad. All piezometers will be installed and constructed in accordance with North Carolina Well Standards. Soil samples will be collected at each drilling location for lithologic descriptions using the standard penetration test (SPT) method with a 140-lb sliding hammer and steel split-spoon samplers. Samples will be collected in 2-feet intervals for every five feet of depth to the completion depth of the boring. The soil retained in each split-spoon sampler will be logged by a geologist with respect to texture, composition, color, and moisture content. In addition, one soil sample collected from the saturated zone at each drilling location will be retained and submitted for grain size analysis at a geotechnical laboratory to allow for estimating the specific yield of the aquifer sediments. Additional soil index testing will be performed on select samples to further characterize overburden soils. The augers, drill pipe, and drill rig will be decontaminated using a pressure washer prior to and following completion of drilling for the project. Each well will be developed after installation using a down hole pump or bailer until the discharge water appears to be free of suspended sediments or for a maximum of one hour. Each well will be surveyed relative to the existing site datum for horizontal position and elevation by a North Carolina licensed surveyor. At each well, elevations will be measured of the ground surface and top of the solid PVC riser. A permanent mark will be made on the top of the PVC riser at the point where the elevation measurement is made for future reference when collecting depth to water data. GROUNDWATER AND SURFACE WATER MONITORING PLAN HORIZONTAL EXPANSION OF THE NASH COUNTY C&D LANDFILL Page 11 of 11 8.2 ABANDONMENT SPECIFICATIONS Locations to be abandoned shall be over-drilled using using hollow-stem augers to remove installed well materials. Bore holes shall be abandoned by tremie grounting, using a cement-bentonite grout. Well materials shall be properly disposed of upon completion.