THE HYDROGEOLOGY OF LAMAR COUNTY, GEORGIA Lee L. Gorday DEPARTMENT OF NATURAL RESOURCES ENVIRONMENTAL PROTECTION DIVISION GEORGIA GEOLOGIC SURVEY Information Circular 80 Cover photo: North of Barne"ville, two drillers in8tall a 6-inch drilled well, uaing a down-the-hole hammer. THE HYDROGEOLOGY OF LAMAR COUNTY, GEORGIA Lee L. Gorday GEORGIA DEPARTMENT OF NATURAL RESOURCES J. Leonard Ledbetter, Commissioner ENVIRONMENTAL PROTECTION DIVISION Harold F. Reheis, Assistant Director GEORGIA GEOLOGIC SURVEY William H. McLemore, State Geologist ATLANTA 1989 Information Circular 80 TABLE OF CONTENTS Page ABSTRACT ........ . ............................................................... 1 ACKNOWLEDGEMENTS ............................................................ 1 INTRODUCTION .. .. ......... .. .. .......... ....... ....... ... ..... .................. 1 PURPOSE ... ....... ... .. .. .. .... . . .. ..... ............... .... .. .... ............ 1 DESCRIPTION OF STUDY AREA .... . ................ . ......... . .............. 2 WELL INVENTORY ............. ....... .... ........ .. ............... . ..... . ... 2 WATER SUPPLY AND USE ............... . ... ................. . ....... ............ 2 GEOLOGY .................. . . .... . . ......... . .. ..... .................. ... . . ....... 6 GENERAL .. .. .... . ....... . . . .. ..... ..... ......................... ............ 6 PREVIOUS INVESTIGATIONS ..... . ....... .. ...... ........... .... . .... .. .... .6 GEOLOGY OF THE AREA NORTH OF THE TOWALIGA FAULT ZONE ........ 8 General ......... ....... ....... ....... ..... ......... .. ..... . .............. 8 Lithologic Units . ... .............. ... ... ... .................. ... .......... 8 Zebulon Formation ................ .... .. . . . .. ................... . ... 8 Ison Branch Formation .......... . ..... .. ............ ........ ......... 8 Barrow Hill Formation ............. ........ . ......................... 8 Clarkston Formation ............ . . . ... ..... ........... ............... 8 Hollonville Granite ........... . . .. ......... ......................... 8 High Falls Granite ............................. .. ... ................. 8 TOWALIGA FAULT ZONE ....... ....... ...... ........... .......... ........... 8 GEOLOGY OF THE AREA SOUTH OF THE TOWALIGA FAULT ZONE ........ 9 General ...................................... ............. ......... .. . . .. 9 Lithologic Units .............................. .... .. .. .. . . .. . ............. 9 Unnamed Schist and Gneiss .................... ....... ............... 9 Unnamed Garnet Granite .......................................... . .9 Manchester Schist ................... ...... .... .. ... ... .. ...... .... ..9 Hollis Quartzite ........................... .. . ......... .... .......... 9 STRUCTURAL GEOLOGY .................... .... ............ . ....... . . ....... 9 GROUND-WATER OCCURRENCE .................... . ..... . ........................ 9 WELL CONSTRUCTION ........... . .. . ......... . ............ . ......... . ........... 11 GROUND-WATER AVAILABILITY .... . ......... . . .. ... .... ... . .................... 11 GROUND-WATER QUALITY ...................................................... 13 GROUND-WATER EXPLORATION TECHNIQUES .. . ............................... 17 TOPOGRAPHIC ANALYSIS ................... ... ....... ..................... 17 AERIAL-PHOTOGRAPH ANALYSIS ........... ........ .. ..... ....... ...... .. . 17 FIELD GEOLOGY ................................... ......................... 22 MAGNETOMETRY ............................ ....... .. ..... .. ............... 22 ELECTRICAL RESISTIVITY ........... ....... ..... ................. .. ... .. ... 24 RECOMMENDATIONS FOR THE SELECTION OF A WELL SITE ................... 25 INTRODUCTION .............................. ... .............. .............. 25 SELECTING A SITE FOR A HIGH-YIELDING WELL .......................... 27 SELECTING A SITE FOR A DOMESTIC WELL ................................. 30 CASE HISTORIES ............................................................ 31 WELL DEPTH ... . .............. ... ....... . .......... . .................. . ........ 34 iii TABLE OF CONTENTS (Continued) Page CONCLUSIONS ..... . . ... . . ...... . ... . . . . .... .... . . . .. .. . ..... . . . ............ . .... 34 REFERENCES .......... . .. ... . .. . .... . . ... ... .. . .... .. . . . ..... . .... . .... .. .. ...... 37 APPENDIX ............. . . . .. . .... . ..... .. . . .... .... ... .... . ...... ....... .......... 39 LIST OF FIGURES Page 1. Location of study area .............................................. . ... .. .. . ... 3 2. Population of Lamar County, 1930 to 1980 with projections to 2000 ... . ... ... ....... 4 3. Physiographic districts in Lamar County ............. . .. . .. . . . ... ...... .. .. . .. . . .5 4. Simple Bouguer anomaly map ................................................... 7 5. Typical construction of wells in Lamar County ....................... . .......... 12 6. Histogram of the yields of wells in the inventory ........................ . . .. ..... 14 7. Piper diagram illustrating the relative percentages of anions and cations .. ... ..... 16 8a. Drainage network in Lamar County. ... .. . . .. ..... . .. . ........ .... . ... ......... 18 8b. Drainage network in Lamar County indicating alignment of streams in a northwest direction.......................................... . ............... 19 8c. Drainage network in Lamar County indicating alignment of streams in a north and north- northwest direction . ........................................... 20 8d. Drainage network in Lamar County indicating alignment of streams in a northeast direction....................................................... 21 9. Composite of photo linears from the stereoscopic examination of high-altitude black and white aerial photographs ... ................ . . . .. .. ... .. . 23 10. Histogram of photo-linear length per 1 square mile cell ........................... 24 11. Histogram of photo-linear intersections per 1 square mile cell .... . ................ 25 12. Areas favorable for the development of ground-water supplies based on aerial photograph analysis .................................................. 26 13. Hypothetical placement of wells near a dipping fault ........................... 27 14. Magnetic profile from Johnstonville northward into the Towaliga fault .. ... .. ..... 28 15. Resistivity soundings in the johnstonville area ............. . .................... 29 16. Theoretically favorable electrical resistivity sounding curve ...................... 30 iv LIST OF FIGURES (Continued) Page 17. Location map of dry holes in relation to a pavement outcrop, eastern Lamar County .......................... . ................. ........... .. ... .. .. 32 18. Location of wells drilled to supply water for irrigation, southwestern Lamar County ... . ..... . .............. ........ ... .. .... . . .. .... . ...... . . ... .. 33 19. Histogram of the depths of wells included in the well inventory .............. ... .. 35 20. Plot of well yield as a function of total depth ................... . .. ..... .. .. ..... 36 LIST OF PLATES 1. Well Location Map .... . ..... .. ............. .. .... .... ........... . pocket envelope 2. Geologic Map .................... . ... . ... .. ........... . .... . ..... pocket envelope LIST OF TABLES 1. Water-Quality Data . .......................... . ..... . ................. ...... . .15 v THE HYDROGEOLOGY OF LAMAR COUNTY, GEORGIA Lee L. Gorday ABSTRACT Wells are the main source of water for domestic supplies in Lamar County. The county is underlain by igneous and metamorphic rocks that have very low primary porosity and permeability. In these crystalline rocks, ground water is stored and transported through discontinuities such as fault zones, stressrelief fractures, lithologic contacts, and smaller scale features such as joints and foliation planes. In order for a drilled well to yield appreciable water, discontinuities such as these must be encountered. Because the volume of the discontinuities in unweathered rock is relatively small, they furnish very little waterstorage capacity. In order for a well to sustain a yield over a long period of time, the discontinuities supplying water to the well must be tied to a source of recharge. Saturated saprolite overlying the crystalline rock is the primary source of recharge to the discontinuities. Ground water for domestic supplies is available in most of the county. Dry holes constitute only a small percentage of the total number of wells drilled. Only one incidence of multiple dry holes has been noted. The average yield of the 69 wells in the well inventory is 24 gallons per minute. The well inventory includes data for all drilled wells for which data could be obtained, mostly domestic wells. Wells drilled in an unnamed schist and gneiss unit south of the Towaliga fault zone have significantly lower yields than the average for Lamar County. Water quality is generally good; although iron, manganese, and fluoride concentrations exceeded recommended limits in several of the wells sampled. Careful selection of a well site will reduce the chances of both inadequate well yield and later contamination of the well. Proper grouting of the well is important for water-quality protection. Topographic analysis, aerial-photograph analysis, magnetometry, and electrical resistivity studies have all proven useful in selecting well sites. In selecting a well site, it is important to consider both sources of potential recharge and sources of potential contamination. ACKNOWLEDGEMENTS would like to thank the many residents of Lamar County who assisted me in compiling the well inventory for this study. With their help, I was able to field locate many wells for which I had no location information. Two people who were particularly patient with my questions were Mr. Frank Patrick, former superintendent of the Barnesville Water Plant, and Mr. Rodney Hilley, County Sanitarian. The cooperation of the water well contractors who serve the Lamar County area was greatly appreciated. Particular thanks are due to Mr. Jerry Colwell and Mr. James Breakey of Middle Georgia Water Systems, to Mr. Hoyt Waller of Waller Well Company, and to Mr. William Martin, Mrs. Mary Dutton, and Mr. Lamar Chastain of Virginia Supply and Well Company ..Mr. Thomas Crawford of West Georgia College, Mr. Charles Cressler of the U.S. Geological Survey, and Mr. Thomas Watson of the Land Protection Branch of the Environmental Protection Division thoughtfully reviewed the manuscript and offered suggestions that were very helpful and greatly appreciated. INTRODUCTION PURPOSE Water is an essential resource that is often taken for granted. In general, Georgia is blessed with plentiful supplies of water, particularly in the Coastal Plain where highly productive regional aquifers are combined with the downstream reaches of the state's major rivers. Lamar County is located in the Piedmont physiographic province (Clark and Zisa, 1976), where the availability of ground water, as well as surface water, is more limited. The Piedmont is the headwaters for many streams. Few streams in the Piedmont have large drainage areas and; thus, very few have large, reliable flows. Ground water in the Piedmont is limited by the geology of the region. Unlike the Coastal Plain, where the depth to a waterbearing unit can be reliably predicted, the depth to a water-bearing zone, or even its existence, generally cannot be predicted in the Piedmont. Consequently, dry holes are sometimes drilled in the Piedmont. The term "dry hole" typically includes not only the holes that yield no water, but also those wells that do not yield an adequate supply for a single residence. Although dry holes are legendary in the Piedmont, they constitute only a small percentage of the total number of wells drilled. 1 The purpose of this study was to make an assessment of ground-water availability in Lamar County. An additional purpose was to investigate techniques that might be useful in siting high-yield wells for use by industries and municipalities and for siting domestic wells to avoid dry, or nearly-dry holes. Several techniques were utilized to point out areas that may be favorable for the siting of highyield wells. DESCRIPTION OF STUDY AREA Lamar County is located approximately 50 airline miles south of Atlanta and is within commuting distance of both Atlanta and Macon (Figure 1). Lamar County occupies the divide separating the Ocmulgee River Basin, which drains into the Atlantic, from the Flint River Basin, which drains into the Gulf of Mexico. Because the county lies on the divide, the drainage areas of the streams within the county are small. The population of Lamar County grew 14 percent from 1970 to 1980 (U.S. Department of Commerce, 1982); a marked increase in growth rate (Figure 2). Population projections suggest a growth rate of approximately 20 percent from 1980 to 2000 (Office of Planning and Budget, 1983). The 14 percent growth in Lamar County's population was in areas outside of Barnesville (U.S. Dept. of Commerce, 1982), the county seat and the only town for which population figures are available. The total area of Lamar County is 186 square miles. Lamar County contains parts of three districts of the Piedmont Physiographic Province (Figure 3). The Washington Slope District of Clark and Zisa (1976) includes the portion of Lamar County that is within the Ocmulgee River Basin. The Washington Slope District is characterized by broad shallow valleys with rounded divides. The portion of the county west of the Ocmulgee River Basin-Flint River Basin divide and north of the base of Pine Mountain is within the Greenville Slope District. Clark and Zisa (1976) characterize the Greenville Slope District as having shallow, open valleys with rounded divides. The remaining part of Lamar County, including Pine Mountain and the area to the south in the Flint River Basin, is in the Pine Mountain District. This district is characterized by the steep, north facing ridge of Pine Mountain and a gently dipping slope to the south with moderate relief. WELL INVENTORY Well data compiled for this study are presented in the Appendix. Each well is identified by sequential numbers that were assigned as the well information became available. The Appendix lists the following information for each well: latitude, longitude, total depth, estimated yield, owner (either at the time of this study, or when drilled), and source of the information. Gaps in the well identification numbers indicate wells for which some of the basic information listed above was not available. U.S. Geological Survey well numbers are included in the Appendix to enable cross referencing between the two sets of well numbers. The U.S. Geological Survey assigns well numbers based on their Index to Topographic Maps of Georgia. Each quadrangle is designated by a number and letter. Letters increase alphabetically northward with I and 0 omitted. Numbers increase eastward. Wells are numbered consecutively within each quadrangle. For example, well 12Y003 is the third well inventoried in the Barnesville quadrangle, and corresponds to inventory number 1 of this report. Plate 1 is a 1:100,000 scale map showing the location of the wells included in the inventory. Some areas of Lamar County contain relatively high concentrations of wells in the inventory. Similarly, there are several large areas for which the inventory contains no wells. The well inventory is not a comprehensive listing of wells in Lamar County. It was often not possible to obtain drill records detailing the depth, yield and other information for known wells. In a number of instances the well records were complete, but the well could not be located. Bored and dug wells are more common than drilled wells in Lamar County; however, this study focused solely on drilled wells. WATER SUPPLY AND USE The city of Barnesville operates a water-supply system that utilizes water from a reservoir on Edie Creek, approximately 5 miles north-northeast of Barnesville. Water-use figures indicate that the Barnesville system withdrew an average of 1.68 million gallons per day (Mgal!d) in 1980. The 1984 data indicates no change in the withdrawal rate. The City of Barnesville supplies water to the William Carter Company and the city of Milner, as well as to residential customers. The Barnesville system utilized ground water for a number of years prior to switching to surface water. Similarly, the City of Milner previously used ground water. Several community water supplies that serve subdivisions and mobile home parks use ground water. Homes that are not within the service areas of public systems or community systems (such as trailer parks or subdivisions) must obtain their own supplies. Domestic supplies are almost exclusively 2 ATLANTA i Jlr 10 0 10 20 MILES Figure 1. Location of study area. The location of adjoining county seats and major metropolitan areas are shown. 3 POPULATION TREND 15,000 r - - - - - - - - - - - - - - - - - - - ------. 14,000 - 13,000 z 0 ~ <( 12,000 ...J ::> a. 0a.. 11,000 I I I I I I ~ I I I I I I I 10,000 9,000 0 l.() ,0..>.. 0 ""<,..D.. ,0..... ,"..".. 0 CX) ,0..>.. 0 ",".."".. 0 0 0 C\J YEAR Figure 2. Population of Lamar County, 1930 to 1980, with projections to 2000. Data from U.S. Department of Commerce (1982] and Office of Planning and Budget (1983]. 4 r m-.-.- : ou l, ~I , C.\M,\ll BUTTS co. --~1~~ .- - - - - - SPALDING CO - --------8-l i---\ ! ' <~ 1 1 ' ' ( ~ ..,_ /~ f ~\-,, ( " l / ' ' 1 01I u N -~ 'I 1\ ' ' - - -I --- LAMAR -- CO. - -.\\, - - - - - - - Jrr.<',. ~-.- J 11: \.. \ \ /' ,,\Ill' -I t, 11'1r.1 , - I / w_,,,, ( ~~-\\ C' . \I t' ~ . '- ' ,..~ v~'' =~- 1 l ! i 'I 0~ I<( I~ 1 ...l _ } / _. e Milner I 11 r I ~~ d REENVILLE !I ( SLOPE ~ )DISTRICT I, ' I \ IJ i ( I gl 8 ~ I r.:l ..... 0 +c-' 70 E c 60 J!2 ~ 50 '+-- 0 z 10 (in thousands of feet) Figure 10. Histogram of photo-linear length per 1 square mile cell. Towaliga fault could be located using magnetometry. the conductivity of the fluid. A number of investiga- Figure 14 indicates that the Towaliga fault zone does tors have used electrical resistivity in prospecting for not exhibit a markedly different magnetic field ground water in crystalline rocks. Scarbrough and strength compared to areas outside the fault. How- others (1969) conducted electrical resistivity profiles ever, there is a large anomaly that occurs in the in the Heflin, Alabama area. Areas of low resistivity, Towaliga fault zone. This anomaly extends over an thought to be associated with the occurrence of area of approximately 700 feet in line B. It is not ground water, were identified. Test drilling of sites known whether the magnetic anomaly is related to selected on the basis of electrical resistivity, seismic the fault. Outside of this anomaly there is little varia- refraction (for depth to bedrock) and topography tion of the magnetic field strength. Magnetometry resulted in well yields (Wilson and others; 1970, p. 13) may be most effective in identifying a single drill site that averaged approximately 8 to 9 gpm. Only one of from one or several small areas of favorability, rather the wells had a yield that would be considered above than as a broad screening technique. average; however, the wells were relatively shallow. Seven vertical electric soundings were conducted ELECTRICAL RESISTIVITY in the Johnstonville area of Lamar County. The resistivity curves of these soundings are presented in Fig- Electrical resistivity is commonly used in assess- ure 15 along with a location map. Sounding 1 was ing sites for water wells. Crystalline rocks generally conducted in the Towaliga fault zone. Sounding 2 ' have a high resistivity due to the fact that the porosity was conducted on the northern margin of the fault and fluid content are low. Fractured rock that con- zone. The remaining soundings were conducted south tains water will tend to have a lower resistivity due to of the fault zone. The soundings utilized an offset 24 en 60 _J _J w (.) u. 0 a: cwo 40 ~ :::::z:> 20 Figure 11. Histogram of photo-linear intersections per 1 square mile cell. multiconductor cable based on the Wenner electrode array. Interpretations of the soundings would amount to speculation in that no well data exist for the immediate area of the soundings. A productive well site in theory would consist, electrically, of a three-layer case. The uppermost layer of unsaturated soil and/or saprolite would have an unpredictable, but intermediate resistivity. Saturated saprolite underlying the upper layer would have a very low resistivity due to the water in the pores and the presence of clay in the saprolite. The third layer, composed of crystalline rocks, would have a high resistivity due to the very low porosity, even if the rock were thoroughly fractured. This theoretically-favorable setting would produce a resistivity sounding curve that would have a shape as indicated in Figure 16. If the difference in resistivity of fractured versus unfractured rock is small compared to the contrast between the rock and the saturated saprolite, it is unlikely that the difference between the fractured and unfractured rock can be detected (T.L. Schmitt, Georgia Geologic Survey, personal communication). In order to assess the degree of fracturing of the bedrock, knowledge of the range of electrical properties of the rock unit would be needed. Some investigators, including Harmon and others (1984) and Carrington and Watson (1984), have utilized alternate electrode arrays in an attempt to better identify fractures in the crystalline rock. Detailed studies at a large number of sites are needed to evaluate the most effective use of electrical resistivity in exploring for ground water. RECOMMENDATIONS FOR THE SELECTION OF A WELL SITE INTRODUCTION A well that produces a reliable supply of clean water must combine three factors. The well must encounter discontinuities in the rock in order to produce a significant flow of water. The discontinuities in the rock must be connected to a source of recharge in order to sustain the yield of the well. Thirdly, the well must be protected from potential sources of con- 25 ol VI u N EXPLANATION I I Top 10% In Fracture-Trace Length and 5 or more Intersections I I A ~ Top 20% In Fracture-Trace Length and 5 or more Intersections j D Top 10% In FracttJre-Trace Length Top 20% In Fracture-Trace Length I'Ll <.~ f,mn IJ S G<~t' ,~ ~W-!.1 ! SJT"~~ l'w m ntll" 1~}31 Gr,f fi,., l'.:l/9 1 I CC'l,OLID Figure 12. Areas favorable for the development of ground-water supplies based on aerial photograph analysis. 26 Well A Well B ' I 0 o o , , ' o 0 ,,o. o ~ . ..... . /ll (JIJ (/ . .... ... . . , .. . .. I0 I / / / 17.& Residual mylonite in soil t?'G7 and saprolite /Discontinuity in the rock Figure 13. Hypothetical placement of wells near a dipping fault. Well A intersects the fault at depth. Well B misses the fault due to failure to take the dip into account. lamination. If any one of these factors is not present, then the well will fail, either in the short or long term. Therefore, the selection of a site to drill should consider these factors. The protection of a well from contamination, through both site selection and construction, has been discussed in the water-quality section. Five techniques for ground-water exploration have been discussed earlier. In selecting a well site, it is advisable to utilize as many techniques as possible in order to increase the odds of success. By utilizing an integrated approach to the selection of a well site, the shortcomings of individual techniques may be overcome. SELECTING A SITE FOR A HIGH-YIELDING WELL The effort devoted to selecting a well site should be proportional to the quantity of water needed and the inherent characteristics of the area. The area under consideration in siting a high-yield well is usually much larger than for most domestic wells. Generally, anywhere from as little as a hundred acres to as much as several square miles may be under consideration. The first step in selecting a site for a high-yield well is to gather as much published or readilyavailable information on the area as possible. The goal of the first stage in the site-selection process is to utilize relatively inexpensive exploration techniques to identify areas that are favorable for further consideration. The information collected should include any available geologic maps, satellite imagery or highaltitude photography. The geologic maps should be examined for features that suggest the presence of water-bearing discontinuities such as fault zones, contacts, and rock units composed of alternating lithologies. The satellite images or high-altitude pho- 27 =-~J 5Q200 /~ ~!160 SOUtH ~:!400 82~60 82300 ~250 5Q2oO B2151i LINE A LINE B Apprlalmcllll! IOUihiiNI h"'tl oJ tl1 'T!M.hi6 /oLl U liMe NOIITH 52300 S22.60 ApPruxP!I'Iele h&r1~ hrnll d/ lhe T'~MJII;d /I!IJ/1 .aortc NORTH 62400 B23eo 82300 82ROO. Figure 14. Magnetio profile frGm Johnslonvill e northw ard into tho Towaliga fault. ~0~----------~----------1~0 ~--------1~0~0--------~1,~000 A Spacing (ml Lin ~ 4 Lin e 6 Line 4 QL---------~--------~1~0--------~10~0~------~1. ~000 A Spacing (ml _.....,_ Measured realstlvlty value - r - Calculated resistivity value u N 4 i - - - - - - - . - - - j :-:ETEA Figure 15. Resistivity soundings in the Johnstonville area. 29 >- f- > il) f- ::J > (/) Cll (/) w il) 0:: +-' :J zf- 0 Vl w .0 Cll z 0:: 0 <( 0... 0... <( Figure 16. 10 100 SPREAD LENGTH (Meters) Theoretically favorable electrical resistivity sounding curve. 1000 tographs, or both, should be examined for linear features that may indicate the presence of discontinuities. Analysis of the geologic maps, satellite imagery, and aerial photographs should indicate areas that may contain water-bearing discontinuities. Topographic analysis can then be utilized to evaluate the recharge potential of the sites. The final step of this first stage in the site-selection process should be to eliminate from consideration any favorable sites that may be adversely affected by sources of contamination. The second phase of the site-selection process utilizes site-specific field studies to identify drilling sites within the favorable areas identified in the first phase. Analysis of low-altitude aerial photography may result in the identification of smaller-scale photo linears than was noted on the high-altitude photographs or satellite images. In addition, the lowaltitude photographs should be used to more accurately locate the previously identified photo linears. Detailed examination of the geology of the favorable areas can identify discontinuities that may provide a pathway for the movement of ground water. Electrical resistivity soundings can be utilized to estimate the thickness and saturation of the regolith as well as to provide clues as to the nature of the rock. Magnetometry can also be used to evaluate the potential for discontinuities in the rock. The final step of the second phase in the siteselection process should be to review the information on each of the potential well sites. At this point, the potential well sites should be compared to evaluate which sites are most favorable for the development of a clean, reliable supply of water. The third phase of the site-selection process is to finally select the site for the well. Ideally this would be the site that is most favorable in a hydrogeologic sense. Other factors, however, may preclude the use of the most favorable site, including a lack of access, distance to point of use, and competing land use. SELECTING A SITE FOR A DOMESTIC WELL The area under consideration for a domestic well is generally only a few acres or less. Consequently, the initial screening that is suggested for selecting a high-yield well site may not be warranted for a domestic well. The first step in the site selection procedure should be to identify potential sources of contamination in the area under consideration and adjacent areas. Random drilling is likely to produce an adequate domestic supply throughout most of Lamar County. However, in order to decrease the risk of inadequate yield, the topographic positions of potential well sites 30 should be compared. A general procedure that can be used by persons with no geological training has been described in the section on ground-water exploration techniques. In addition to topographic position, the thickness of the regolith should be considered. Although it is not possible to easily measure the regolith thickness without drilling or boring equipment, pavement outcrops and areas with large boulders in the soil can be easily identified and should be avoided as drill sites. Analysis of low-altitude aerial photographs is recommended in areas where well yields are known to be low. For the selection of a domestic well site, one must identify the photo linears that may be related to discontinuities that provide an avenue for the movement of ground water. Local Agricultural Stabilization and Conservation Service (ASCS] offices maintain several series oflow-altitude aerial photographs. Copies of the photos can be ordered through the ASCS. Selecting a site for a well on a piece of property of one acre or less can present major problems. If a septic system is used on the property, then the area left for the well, after allowing for prescribed minimum separations, is limited. This problem is compounded if septic systems on adjoining parcels are located near the property line. Even without having to maintain the separation from a septic system, the range of sites available for the well on a small piece of property is limited. It is recommended to always establish the water supply before initiating construction. CASE HISTORIES Attempts to develop a water supply on two pieces of property provide evidence that supports present theories on the selection of well sites. Both of these sites are located within the area of the unnamed schist and gneiss unit, which has lower average yield than other rock units in the county. Problems have been encountered in developing a reliable domestic supply to replace a dug well at a residence on Galvin Bush Road, just south of US 41. The Appendix includes the records of three wells [numbers 19, 21, and 44, Plate 1] that have been drilled on this property. A fourth drilled well was started on the property, but was abandoned prior to the intended depth owing to the loss of the drilling tools in the hole (Paul Milner, former resident, personal communication]. A pavement outcrop is present within 500 feet of each of the wells. None of these wells produced an adequate yield to supply the residence. Figure 17 shows the location of the wells and the pavement outcrop. An analysis of the well sites based on topo- graphy and soil thickness, such as the LeGrand (1967) method, indicates that these sites are not favorable for the development of a reliable water supply. The thin regolith (19 feet based on casing lengths] and proximity to a pavement outcrop suggest that even if a water-bearing discontinuity had been encountered, that the potential for recharge to the well is limited. The existing dug well was eventually replaced by a bored well located at a lower elevation than the three drilled wells. The bored well location was chosen by the property owner so that it would lie along a photo linear detected on lowaltitude aerial photographs [Vernon Heinline, property owner, personal communication]. Four wells were drilled to develop a water supply to irrigate a pecan orchard in southern Lamar County. The orchard is located on Finney Lake Road, west of Highway 36. Figure 18 shows the sites of the four wells at the orchard along with three other nearby wells for which records are available (see the Appendix]. The approximate location of a photolinear detected on the high-altitude black-and-white photographs is included on Figure 18. Wells 62, 63, and 64 are all located near the crest of a hill, which means that the potential for recharge to the well is limited. Well 63, and to a lesser extent, well 64 are near minor linear stream segments. Wells 62, 63 and 64 are not particularly favorable sites for a highyielding well considering the large area that was available. The yields of these wells [from 1 to 4 gpm) would be adequate for a domestic supply, especially considering the volume of water in storage in the deep well bore. However, in terms of supplying water for irrigation, the yields are inadequate. Well65, in contrast to wells 62, 63 and 64, is in a location that is favorable both in regard to the occurrence of water-bearing discontinuities and to recharge potential. This well is located next to a photo-linear observed on the high-altitude black-and-white photographs and to the intersection of a linear stream segment with a linear intermittent stream. The linear stream segment is aligned with another linear stream segment across the hill and to the southeast (Figure 18). The combined length of these linear stream segments is 6000 feet. This site, based on the topography and the high-altitude aerial photography is the most favorable site in the pecan orchard. The driller estimates the yield of the well to be 20 gpm. Although this well has a yield that is average with respect to the county as a whole, the yield is nearly double the average for wells in this rock unit. The wells at the pecan orchard produce yields that are in keeping with the relative favorability of the sites. Three additional wells are plotted on Figure 18. Because well49 is located next to a long linear stream segment, it occupies a topographic position that is 31 N Well data is listed by inventory number in Appendix A 0 200 400 600 800 Figure 17. Location map of dry holes in relation to a pavement outcrop, eastern Lamar County. 3Z Bose from U.S. Geological Survey Bar-nesvllkt, Ge. 1:24,000, 1973 and Yatewille, Ga 1:24,000, 1973 Figure 18. Location of wells drilled to supply water for irrigation, southwestern Lamar County. Orchard to be irrigated is outlined. Shaded area indicates the location of a photo-linear from high-altitude, black-and-white photography. Map from portions of the Barnesville and Yatesville 7.5' U.S. Geological Survey Maps. 33 more favorable for producing a given supply than wells 45 and 46 or wells 62 and 64. The records of these wells, however, indicate that the yield of wells 45 and 46 are several times the yield of well 49. Therefore, although the apparent favorability of a site can be evaluated, the actual yield cannot be known until a well is drilled. WELL DEPTH The average depth of the drilled wells in the inventory is 296 feet. Drilled well depths range from a 53 ft. deep, 30 gpm well (29) to a 780ft. deep dry hole (44). The percentage of wells falling into a number of depth ranges is indicated as Figure 19. This figure indicates that 59% of the wells in the inventory were 300 feet deep or less. Figure 20 is a plot of well yield versus depth. The random scatter of the data points indicate that well yields correlate poorly with depth. Yields of wells that are 500 feet deep or more, however, are generally low. Similar statistics in other areas led LeGrand [1967) and Snipes and others (1984) to suggest that there is a lower probability of obtaining water at deeper depths. A more likely explanation for the generally low yields of deep wells is that the wells are deep only because an adequate yield was not obtained at a shallower depth. The lower yields of the deep wells are probably due to the lack of secondary permeability in that specific area rather than a general decrease in the number of fractures with depth. The question of how deep to drill a well is one of the most difficult questions in the field of crystallinerock hydrogeology. LeGrand (1967, p. 5) recommends maximum depths of between 150 to 300 feet. Cressler and others (1983, p. 53) state that drilling beyond 650 feet, without other information, usually can not be justified. Snipes and others [1984, p. 16-20) report well yield statistics indicating a tendency toward higher yield and productivities (yield divided by the open length of the well) at shallower depths. This trend is attributed to decreasing fracture density and opening size with depth (Snipes and others, 1984, p. 20). Fenix and Scisson, Inc. (1964) conducted a study on the feasibility of constructing a natural gas storage cavern north of Milner. Six core holes were drilled at the site. Fenix and Scission Inc. (1964, p. 7) report that open fractures occurred in all six holes. The test drilling indicated that open fractures are most common from the surface to a depth of approximately 275 feet and below 400 feet to the total depth of the holes. Selected 22 foot intervals were tested with straddle packers to measure the flow rate under a surface gauge pressure of 75 psi. Four of the six test holes had zones that accepted water at a rate that would not allow for a build up of pressure. The flow rates of these zones were not determined, but are known to exceed 0. 75 gpm. The high-flow rate zones occurred at depths ranging from 287 to 530 feet. Test depths ranged from 266 to 572 feet. R.D. Bentley's description of core from the test holes (Fenix and Scisson Inc., 1964, Appendix A) notes occurrences of feldspars being altered to kaolinite in each of the holes. The presence of kaolinite indicates considerable groundwater flow through the rock. The data from the propane storage site indicates that avenues of groundwater flow exist at depths exceeding 500 feet in Lamar County. Little data are available concerning the occurrence of ground water at depths exceeding 600 to 700 feet. However, Seeburger and Zoback (1982) note little, if any, decrease in fracture density with depth in wells of 3000 feet or more. The depth at which to abandon a hole and drill at another location depends on the nature of the site and the conditions encountered. This aspect of well drilling is a common subject of debate for well drillers and geologists. The following general guidelines for domestic wells seem reasonable, based on the data collected and reviewed as a part of this study; however, site-specific conditions may dictate other guidelines. Abandoning a well at a depth of less than 450 feet may be premature. If some water has been obtained, but more water is needed, drilling to depths of 600 feet or more may be appropriate if the rock is exhibiting changes in texture or lithology. Drilling beyond 600 to 700 feet may not be feasible due to high drilling costs; however, ground water may be available beyond those depths. If the yield has increased in the previous hundred feet of drilling, and the well is approaching the desired yield, then continued drilling is advised. In the event that initial efforts are unsuccessful, or if problems are encountered, it is recommended that an experienced ground-water professional be consulted. CONCLUSIONS Ground water in Lamar County occurs in discontinuities in the essentially impermeable crystalline rock and in pore spaces in the regolith overlying the rock. Discontinuities in the rock that may provide pathways for the movement of ground water include faults; contacts between rock units; stress relief fractures; and smaller scale structures, such as planes of foliations and joints. Because the primary permeability of the rock is very low, most wells must encounter a discontinuity to produce an adequate yield. Well records from 69 drilled wells are available in Lamar County. Most of the wells included in the 34 100 ~-------------------------------------------,r- 80 ....>...- 0 c: Q) i; 60 c: rn -1 0 Q) 40 ...Oro'l c: Q) .0... &. Figure 19. 0-100 101- 201- 301- 401- 200 300 400 500 Well depth in feet 501- 601 600 & up Histogram of the depths of wells included in the well inventory. Both the percentage of wells in the survey and the cumulative percentage of the corresponding depth range and shallower are plotted. inventory are for domestic use; therefore, few of the wells were drilled for maximum yield. Thus, the data base is skewed toward shallow, low-yield wells drilled at sites that were selected based on convenience. The average yield of the wells in the inventory is 24 gpm. The wells range in depth from 53 feet to 780 feet with an average depth of 296 feet. Well yields in a schist and gneiss unit in the southern half of the county are significantly lower than in rock units elsewhere in the county. Four of the five dry holes noted in the inventory are located in this low-yielding schist and gneiss unit. The water from drilled wells in Lamar County is of the calcium and sodium bicarbonate type. Total dissolved solids values are generally low. Iron and manganese concentrations exceed the recommended drinking water limits in seven of the twenty-one wells tested. Although the iron and manganese are a nuisance to the well owners, there are no known health risks associated with iron or manganese in ground water. Fluoride concentrations exceeded drinking water limits in two wells. The high fluoride concentrations may result in the mottling of tooth enamel in children. The drilling of a well in Lamar County, and in the Piedmont province in general, always carries the risk of a dry or nearly dry hole. With adequate storage, however, as little as 1 gpm can supply the needs of a single residence. Careful selection of the location of a well can increase the chances of producing the desired yield. Property owners with no training in geology can compare potential well sites based on 35 YIELD (GALLONS 'PER MINU;T.El 0 0 10 I 20 30- 40 I I I 50 60 1 I 100 r- 200 r- I - u1ww-. 300 r- -~ :t: E: ~ 4001- 500 1- 600 1- 70'0 r-. >70 100 105 300 I I I I I I Figure 20. Plot or w ell yield as a function of total depth . 36 topography and soil cover. By examining the topography and soil cover of a property, it is possible to identify areas where the discontinuities that control the movement of ground water are more likely to occur. In general a topographically-low site is more likely to produce a desired yield than a topographically-high site. Linear features can be utilized to identify places where discontinuities in the rock are likely. These linear features may include stream segments, changes in slope, heartiness of vegetation and soil tone. It is important that the linear features be natural and not man-induced. Although the drainage pattern in Lamar County is generally dendritic, the alignment of some smaller streams suggests that there is a degree of underlying geologic control on the location of drainages, and that the drainage systems are not entirely superimposed, if at all. Electrical resistivity, magnetometry and analysis of aerial photographs can all be helpful in identifying sites for productive wells in a fractured-rock terrain. These methods have been utilized in Lamar County. However, the effectiveness of these methods can not be statistically evaluated because of the limited well data available. In selecting a site for a well, it is important to use as many selection techniques as practical. In this way, the drawbacks of the individual methods can be minimized. The potential for recharge and the potential for contamination are of critical importance in selecting a well site. The discontinuities that provide pathways for ground-water flow store little water. Therefore, in order for a well to provide a continuous yield, the fractures must be connected to a source of recharge. Water stored in the unconsolidated material overlying the rock is the main source of recharge. Potential recharge increases as the thickness of the unconsolidated cover increases and as the watershed upslope from the well site increases in size. Potential sources of contamination to a drilled well include septic tanks, feed lots, waste impoundments, landfills, and chemical and pesticide storage areas. Maintaining a safe distance from these sources, particularly if the well is down-slope, reduces the risk of well contamination. The most favorable area for the development of high-yielding wells in Lamar County, based on the information compiled for this report, is in the Towaliga fault zone. Northeast of Barnesville, the Towaliga fault zone is located in the valley of the Little Towaliga Creek, which has a sizeable drainage area. The resistivity studies indicate that the thickness of saprolite may be greater within the fault zone than outside of the fault. The rocks of the Towaliga fault zone include fractured mylonite. The Towaliga fault zone is an area of known shearing which may have pro- duced pathways for ground-water flow. The existence of a number of factors suggesting the presence of discontinuities and the excellent potential for recharge make the fault zone a likely area for the development of high-yielding wells. REFERENCES Atkins, R.L., in review, Geology of the granites and gneisses of the Cedar Rock Complex: Georgia Geologic Survey. Brook, G.A., Sun, C., and Lloyd, T.S., 1984, Geological factors influencing well productivity on the Georgia Piedmont: Technical Completion Report ERC 05-84, Environmental Resources Center, Georgia Institute of Technology, Atlanta, 91 p. Carrington, T.J., and Watson, D.A., 1981, Preliminary evaluation of an alternate electrode array for use in shallow-subsurface electrical resistivity studies: Ground Water, v. 19, p. 48-57. Clark, W.Z., and Zisa, A.C., 1976, Physiographic map of Georgia: scale 1:2,000,000, Department of Natural Resources, Geologic and Water Resources Division (Georgia Geologic Survey), Atlanta, Georgia. Clarke, J.W., 1952, Geology and mineral resources of the Thomaston Quadrangle, Georgia: Georgia Geologic Survey Bulletin 59, 99 p. Cressler, C.W., Thurmond, C.J., and Hester, W.G., 1983, Ground water in the greater Atlanta region, Georgia: Georgia Geologic Survey Information Circular 63, 144 p. Crickmay, G. W., 1952, Geology of the crystalline rocks of Georgia: Georgia Geologic Survey Bulletin 58, 54 p. Favilla, L.J., 1985, A gravity survey of Lamar County, Georgia: Georgia Geologic Survey Open-File Report 86-3, 33 p. Fenix and Scisson, Inc., 1964, Feasibility report, mined LP gas storage cavern for Dixie Pipeline Company: unpublished consulting report, 120 p. Furcron, A.S. and Teague, K.H., 1943, Mica-bearing pegmatites of Georgia: Georgia Geologic Survey Bulletin 48, 192 p. Grant, W.H., 1967, Geology of the Barnesville area and Towaliga fault, Lamar County, Georgia: Georgia Geologic Survey Guidebook 6, 16 p. Harmon, D.H., Watson, D.A., and Duffey, T., 1984, Georgia's Piedmont ground water: Water Well Journal, v. 38, p. 33-38. 37 Hem, John D., 1985, Study and interpretation of the chemical characteristics of natural water, 3rd ed.: U.S. Geological Survey Water-Supply Paper 2254, 263 p. Hewett, _D.F., and Crickmay, G.W., 1939, The warm springs of Georgia, _their geologic relations and origin, a summary report: U.S. Geological Survey Water-Supply Paper 819, 37 p. Higgins, M.W., and Atkins, R.L., unpublished, Geological maps of the Griffin and Thomaston, Georgia, scale 1:100,000 quadrangles. On file at the U.S. Geological Survey, Doraville office. Higgins, M.W., and Atkins, R.L., 1981, The stratigraphy of the Piedmont southeast of the Brevard zone in the Atlanta, Georgia area, in Wigley, P.B., ed., Latest thinking on the stratigraphy of selected areas in Georgia: Georgia Geologic Survey Information Circular 54-A, p. 3-40. Higgins, M.W., Atkins, R.L., Crawford, T.J., Crawford, R.F., III, and Cook, R.B., 1984, A brief excursion through two thrust stacks that comprise most of the crystalline terrain of Georgia and Alabama: Georgia Geologic Society 19th Annual Field Trip Guidebook, Atlanta, 67 p. Jammallo, J.M., 1984, Use of magnetics to enhance identification of bedrock fracture trace zones for well locations, in Nielson, D.M., and Curl, M., eds., NWWA/EPA conference on surface and borehole geophysical methods in ground water investigations: National Water Well Association, Worthington, Ohio, p. 105-133. LaForge, L., Cooke, W., Keith, A., and Campbell, M.R., 1925, Physical geography of Georgia: Georgia Geological Survey Bulletin 42, 189 p. LeGrand, H.E., 1967, Ground water of the Piedmont and Blue Ridge Provinces in the Southeastern States: U.S. Geological Survey Circular 538, 11 p. Lehr, J.H., Gass, T.E., Pettyjohn, W.A. and DeMarre, J., 1980, Domestic water treatment: McGraw Hill, New York, 264 p. North American Commission on Stratigraphic Nomenclature, 1983, North American stratigraphic code: American Association of Petroleum Geologists Bulletin, v. 67, p. 841-875. Office of Planning and Budget, 1983, Population projections for Georgia counties, 1990 and 2000, Atlanta, p. 9. Penley, H.M., and Sandrock, G.S., unpublished, Reconnaissance geological map of Lamar County, scale 1:63,360. On file at the Georgia Geologic Survey, Atlanta. Scarbrough, W.L., Joiner, T.J., and Warman, J.C., 1969, Electrical resistivity survey in the Piedmont area, Alabama: Geological Survey of Alabama Circular 57, 20 p. Seeburger, D.A., and Zoback, M.D., 1982, The distribution of natural fractures and joints at depth in crystalline rock: Journal of Geophysical Research, v. 87, p. 5517-5534. Snipes, D.S., Barnett, L.L., Wylie, J.A., Sacks, L.A., Heaton, S.B., Dalton, G.A., Israel, B.A. and Padgett, G.G., 1984, Indicators of ground water quality and yield for a public water supply in rock fracture zones of the Piedmont: Water Resources Research Institute Report 115, Clemson University, 80 p. Stafford, D.B., Ligon, J.T., and Snipes, D.S., 1983, Fracture trace mapping and water well yield in the Piedmont region of South Carolina: Water Resources Research Institute, Report 112, Clemson University, 66 p. Staheli, A. C., 1976, Topographic expression of superimposed drainage on the Georgia Piedmont: Geological Society of America Bulletin, v. 87, p. 450-452. Stieve, A.L., 1984, Petrologic variation of the granulites and related gneisses of the Pine Mountain Terraine, Georgia: unpublished M.S. thesis, Emory University, Atlanta, 107 p. Stewart, J.W., 1964, Infiltration and permeability of weathered crystalline rocks, Georgia Nuclear Laboratory, Dawson County, Georgia: U.S. Geological Survey Bulletin 1133-D, 59 p. U.S. Bureau of the Census, 1982, 1980 census of population, volume 1, characteristics of the population, Chapter A, number of inhabitants, part 12, Georgia: U.S. Department of Commerce, p. 9. Voytek, J., Jr., 1986, Hard drilling through hard rock: Water Well Journal, v. 40, p. 57-59. Watson, T.W., 1984, Hydrogeology of Greene, Morgan and Putnam Counties: Georgia Geologic Survey Information Circular 60, 16 p. Wilson, G.V., Joiner, T.J., and Warman, J.C., 1970, Evaluation, by test drilling, of geophysical methods used for ground water development in the Piedmont area, Alabama: Geological Survey of Alabama Circular 65, 15 p. Subsequent to the preparation of this report the Zebulon, Ison Branch, and Barrow Hill formations were formally described in: Higgins, M. W., Atkins, R.L., Crawford, T.J., Crawford, III, R.F., Brooks, R., and Cook, R.B.: U.S. Geological Survey Professional Paper 1475, 173 p. 38 APPENDIX - WELL RECORDS Inventory Numb 0 1 Barnesville Community Park 2 Paul Milner 3 Crystal Springs Park 4 Kendall's Mobile Home Park 5 Copeland Milner Latitud 33 05' 01" 33 05' 49" 33 09' 24" 33 07' 09" 32 59' 22" L 'tud' 84 10' 19" 84 05' 51" 84 05' 17" 84 10' 35" 84 07' 55" Casing Depth Diameter Length (feet) (inches) (feet) 395 6 97 187 6 90-100 205 6 70 124 6 65 112 6 25 Yield (-g-pm) 61 7 45 20 1.5 Specific Capacity (gpm/ foot of ruawd 0.31 - - - 0 .1 4 Year Drilled 1971 1963 - - 1961 Drill Unknown Waller Askew Morris Waller Va. S & W. . U.S.G.S. .................. 12Y003 13 YQOJ 13Z001 12Y004 12X002 6 Liz Acres Subdivision 7 W.C. Hudgins 8 Milner School 33 04' 58" 84 10' 25" 165 8 32 58' 08" 84 06' 48" 144 6 33 07' 02" 84 11' 56" 263 6 - 100 85 8 - 1946 Va.S&W. - 1956 Va. S &W. 87 102 1.27 1945 Va. S &W. 12Y00 5 13X001 12Y001 9 Herman Davis 33 07' 14" 84 11' 20" 180 6 77 30 0.75 1951 Va. S &W. 1 2 Y0 4 5 10 Maude Wilson 33 06' 56" 84 12' 02" 241 6 62 50 1.43 1951 Va. S & W. 12YOOB 11 J.E. Trice 33 04' 54" 84 12' 59" 100 6 34 0.35 - 1944 Va. S &W. 13Y 002 12 J.J. Darden 33 07' 08" 84 11' 44" 225 8 86 15 0.15 1945 Va. S &W. 12Y007 13 U.S. Engineers #1 33 09' 13" 84 12' 34" 375 8 120 53 0.41 1942 Va. S & W. 12Z003 15 City of Milner 33 07' 00" 84 11' 48" 600 6 90 23.7 0.14 1965 Va. S &W. 12Y008 ""'' 16 City of Barnesville 17 Jim Graham 33 04' 11" 84 09' 22" 400 6 30 300 - 1908 Unknown 32 59' 30" 84 10' 22" 230 6 34 35 - 1978 Waller 13Y 009 12X003 18 Joe McGaha 33 03' 52" 84 07' 54" 238 - 34 18 0.2 1951 Va. S &W. 12Y010 19 E.C. Milner 33 02' 57" 84 05' 34" 509 6 - 0 - 1951 Va. S &W. 13Y003 20 Paul Milner 33 04' 51" 84 06' 05" 146 6 104 5 0.05 1950 Va.S&W. 13Y004 21 E.C. Milner 33 02' 57" 84 05' 34" 355 6 19 0 - 1950 Va.S&W. 13Y005 23 Major Andrews 33 03' 40" 84 11' 16" 154 6 95 25 - 1950 Va. S &W. 12Y011 24 B. Lloyd Woodall 33 04' 57" 84 10' 23" 260 6 147 20 0.67 1948 Va. S&W. 12Y012 25 Dr. S. B. Taylor 33 02' 22" 84 14' 47" 328 6 56 5 - 1946 Va. S &W. 12Y013 26 F.J. Stocks 33 03' 54" 84 08' 04" 116 6 38 14 - 1943 Va. S &W. 12Y014 27 M.L. Ball 28 U.S. Engineers #2 33 09' 13" 84 06' 24" 157 6 64 12 0.08 1951 Va. S &W. 33 09' 04" 84 12' 30" 76 8 28 30 - 1942 Va. S &W. 13Z002 12Z004 29 Ruth Martin 33 06' 38" 84 13' 34" 43 6 32 20 0.5 1950 Va. S &W. 12Y018 30 341 Mobile Home Park 33 01' 11" 84 08' 01" 225 6 105 25 - 1967 Waller 12Y019 32 Triple H. Farms 33 04' 39" 84 13' 17" 545 6 40 5 - 1981 Waller 12Y020 33 Mrs. Fred Hand 33 05' 34" 84 07' 35" 415 6 51 6 - 1981 Waller 12Y0 21 34 William Lovejoy 35 Jerry Hayes 33 02' 17" 84 12' 03" 305 6 46 3 33 05' 06" 84 05' 25" 205 6 25 10 - 1981 Waller - 1981 Waller 12Y022 13Y006 36 W.A. Rowell 40 Roger Legg 33 07' 21" 84 14' 35" 205 6 35 10 32 58' 50" 84 06' 46" 525 6 - 0 - 1981 Middle GA - 1979 Waller 12Y023 13X002 41 Roger Legg 32 58' 49" 84 06' 46" 205 6 30 30 - 1979 Waller 13X003 42 Rex Coplen 33 05' 43" 84 14' 52" 285 6 86 25 - 1979 Waller 12Y024 APPENDIX - WELL RECORDS/Continued Inventory Number Owner Latitude Longitude Casing Depth Diameter Length (feet} (inches) (feet) Yield (gpm) Specific Capacity (gpm/ foot of drawdown) Year Drilled Driller U.S.G.S. Well Number 43 United Pentecostal Church 33 10' 24" 84 05' 02" 260 6 80 40 - 1979 Waller 13Z003 44 Vernon H ineline 33 02' 58" 84 05' 34" 780 6 18 0 - 1971 Askew Morris 13Y007 45 Ponderosa Inn 33 00' 09" 84 11' 33" 87 6 30 23 - 1961 Adams 1 2 Y02 5 46 Ponderosa Inn 33 00' 09" 84 11' 34" 405 6 35 35 - 1977 Middle GA 12Y026 47 Jellystone Park 33 10' 02" 84 02' 34" 505 6 57 15 0.07 1970 Va.S &W. 13Z004 48 Jellystone Park 49 George Click 33 10' 10" 84 02' 39" 455 6 52 45 0.75 1970 Va. S &W. 32 59' 39" 84 11' 34" 345 . - 4 - 1984 Bedsole 13Z005 12X004 50 Donnie Wallace 51 Beamer Donahoe 33 05' 34" 84 10' 46" 425 6 19 50 33 03' 56" 84 10' 51" 125 6 - 15 - 1984 Interstate - 1974 Aqua 12Y027 12 Y02 8 52 Tom Bodkins 53 Billy Weaver 54 C.B. Cole 33 04' 55" 84 07' 52" 325 6 85 15 - 1984 Va. S &W. 33 02' 43" 84 06' 39" 294 6 20 3.5 - 1979 Bedsole 33 03' 04" 84 14' 46" 165 6 - 5 . 1971 Bedsole 12Y029 13Y008 12Y030 55 Charley Jones 33 01' 58" 84 09' 39" 405 6 68 25 - 1977 Askew-Morris 12Y031 56 Donald Royal "0 " 58 William Key 33 01' 56" 84 09' 39" 400 6 - 4 - Va. S &W. 33 06' 35" 84 13' 30" 180 6 40 12 - 1985 Bedsole 12Y032 12Y033 59 H.S. Turner 60 Jeff Baker 61 Milton Pritchett 62 Harry Poole #1 63 Harry Poole #2 64 Harry Poole #3 65 Harry Poole #4 66 Marion Underwood 67 Carl Sawyer 68 Joseph Bush 33 01' 33" 84 09' 19" 210 6 201 15 0.11 1968 Va. S &W. 33 03' 23" 84 03' 46" 430 6 - 20 - Morgan 12Y 034 13Y009 33 03' 14" 84 11' 21" 465 6 11 12 . 1974 Askew-Morris 12Y0 35 33 00' 05" 84 12' 11" 705 6 30 1.5 - 1985 Va. S &W. 12Y036 33 00' 01" 84 12' 17" 605 6 58 4 - 1985 Va. S &W. 12Y037 32 59' 55" 84 12' 20" 465 6 7 1 - 1985 Va. S & W. 12Y005 33 00' 23" 84 12' 12" 625 6 20 25 - 1985 Va. S &W. 12Y038 33 01' 49" 84 10' 53" 265 6 42 2 - 1956 Va.S &W. 12Y039 33 03' 56" 84 13' 27" 165 6 - 10 - 1966 Waller 12Y040 33 01' 54" 84 06' 38" 104 6 - 5 - 1967 Waller 13Y010 69 Robert Paris 33 04' 25" 84 04' 14" 285 6 70 Dan Faulkerson 33 09' 28" 84 08' 32" 175 6 72 Dale Vaughn 33 05' 00" 84 08' 11" 345 6 73 Mt. Pleasant Baptist Church 33 01' 11" 84 14' 49" 285 6 74 Tony Mark Turner 33 00' 23" 84 11' 56" 245 6 - 15 - 25 50 2.5 100 12 - 8 - 1986 Waller 13Y011 - 1986 Morgan 12Z006 - 1986 Waller 12Y041 - 1986 Middle GA 12Y042 - 1986 Askew-Morris 12Y043 75 Sarah Lemmons 33 10' 20" 84 12' 27" 230 6 104 25 - 1986 Askew-Morris 12Z005 76 Billie Sue Bean 33 11' 33" 84 07' 08" 105 6 - 50 - 1986 Askew-Morris 13Z006 77 , Triple H. Farms -- 33 04' 39" 84 13' 15" 725 6 - 0 - 1981 Waller 12Y040 United S tates Geolog ical Survey well numbers are included inthe Appendix to enable cross referencing between the tw o se ts of weU numbers. The U.S. Geological S urvey assigns well numbers based on their Ind ex to Topographic Maps of Georgia . Each quadr a ng le is designated by a number and le ller. Letters increase alp habetica.lly northward with 1 and 0 omitted. N umbers increase east ward. Wells are nu mbered consecu tively within each quadrangle. For example. well 12Y003 is the third well inventoried in the Barnesville quadrangle. and corresponds to inventory numb er 1 of this report. --------SP-A-LD-IN;G-C-O-. \ 81 I N u LAMAR CO. I I I 25/4 2 ( I I GEORGIA GEOLOGIC SURVEY INFORMATION CIRCULAR 80 PLATE 1 ----,------ 2.5/72 1 5/52 I I I I I I I ~-~: ~ I I I I I e 5/54 I ,--~ r--JI )' I 1 \ P' -I K-E- -C-O-. + UPSON CO. 0 0 2 5/65 23/4 5 1. 5/62 @36 /46 4 /63 e 1/64 . 35/17 - - - - - - -LA-.M-A-R-C-O-. 2 3 4 5 6 2 3 4 Ml STUDY I II 8/ 7 First number Is well yield in gallons per minute Second number Is Inventory number I I I Creek I "~ I I I I I Base from U.S. Geological Survey Thomaston 1981, Griffin 1979 1 : 100,0 0 0 LI ______ _ ~ MONROE CO. I _ _ _ _ _ __JI WELL LOCATION MAP _________S_PA_LiDIN_G_CO_. \ 81 I N u II. GEORGIA GEOLOGIC SURVEY INFORMATION CIRCULAR 80 PLATE 2 BUTTS CO. 0 C) ~ 0 z ~ 0 ~ ____ _ \I ,.P_IK. E CO. .STUDY I UPSON CO. 0 0 &-mb -------L-A-M-A-R-C-O-. 2 3 4 5 6 2 3 4 Ml EXPLANATION UNITS NORTH OF THE TOWALIGA FAULT UNITS SOUTH OF THE TOWALIGA FAULT Clarkston formation unnamed garnet granite Barrow Hill formation unnamed gneiss and schist Ison Branch Formation Hollis Quartzite Zebulon formation Lit-par-lit metamorphosed Zebulon formation ~ ~. Contact metamorphosed Zebulon formation High Falls granite Hollonville granite Manchester Schist OTHER UNITS Towaliga fault zone micro breccia alluvium pegmatite (location approximate) I Creek I p ~0. I I I I I I I I I I I I p ,--'II p LI ______ _ ~ MONROE CO. I _ _ _ _ _ _JI Base from U.S. Geological Survey Thomaston 1981, Griffin 1979 1:100,000 GEOLOGIC MAP