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Home My WebLink AboutSW3170803_COMPLIANCE_20171012STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. I DOC TYPE I ❑ CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE COMPLIANCE EVALUATION INSPECTION DOC DATE YYYYMMDD October 12, 2017 Consulting Engineers GEoSC1ENCE GROUP MPV Properties. c/o Urban Design Partners 1318-e6 Central Avenue Charlotte, North Carolina 28205 Attention: Mr. Brian D. Smith, P.E. Reference: Estimation of Seasonal High Groundwater Table Reafield Union County, North Carolina Geoscience Project No. CHI6.0107.GE This letter provides you with our estimate of the Seasonal High Groundwater Table at the location of the detention pond proposed for the western portion of the site. Subsurface Data: One (1) soil test boring (P-1) was advanced in the area of the proposed detention pond at the approximate location shown on the attached Boring Location Diagram, Drawing No. CH17.0149.CO-1. This boring was advanced to a termination depth of 25 feet below the ground surface. Upon completion of drilling, a temporary piezometer consisting of 1 inch diameter continuously slotted polyvinyl chloride (PVC) pipe was installed in the boring from the ground surface to the boring termination depth. Water level readings were taken in the piezometer 24 and 48 hours after it was installed. The piezometer was removed after the 48 hour water level reading and the auger hole was backfilled to the ground surface with the auger cuttings. The subsurface conditions starting at the exposed ground surface consist of a dense to very dense brown, grey and black silty coarse to fine SAND. This soil structure extends to a depth of approximately 8 feet and has a very low plasticity. Partially weathered rock consisting of a silty coarse to fine SAND is present beginning at a depth of approximately 8 feet below the ground surface. This very dense soil structure extends to the boring termination depth of 25 feet. Groundwater was observed approximately 48 hours after the boring was drilled at a depth of approximately 6% feet below the ground surface. Based on the Grading Plan referenced above and our visual estimate of the depth of recent excavation in the vicinity of the soil test boring, this groundwater depth corresponds to an elevation of 5773/4 feet (MSL). Conclusions: Based on the results of soil test boring P-1, our visual classification of the soil samples, the moisture conditions of the soil samples, and the groundwater level reading, the Seasonal High Groundwater Table at the location of the proposed detention pond appears to be near elevation 580 feet (MSL). If you have any Daniel A. N Senior Vice North Carol this information, please contact us. 24977 500 Clanton Road Suite K Charlotte. North Carolina Telephone Facsimile NC License 28217 704,525.2003 704,525,2051 F-M5 . - FG%,,R11D-blTBt4'y1.— �4 ------------ 11 ,.ten •ISM.., R�p� �� ! r ime» i • _.Woo s e eNr «ecy 1 w�- 'y, �� Ie": ij ..m's i'-�r'w�arMpay.• REAFIELD UNION COUNTY, NORTH CAROLINA BORING LOCATION DIAGRAM DRAWING NO. CHI 7.0148.CO-1 APPROXIMATE SCALE: 1• = B0' APPROXIMATE BORING LOCATION IF >, p-1 `LOT 1`�i..- � I - I LOT 2 I LOT 3 I LOT a - SEE SHEEP C4.1 FOR ouET � e e GE°SCIENCE GROUP u� 0.ttmeae, 17 Fw. AISR2003 Fa. 101.535.3d51 wr.M.9mBdaR¢ogmn BORINONOc.._..1��_ DAIL-MI d.M, , DRILLIN6OONMC'r0R: JOB NO., C1117.014%C0 DEPTH, FT. DESCRIPTION Elev. 0.0 584 0 3.1 5.1 8.1 22.( 25.0 TEST. BORING GEOSCIENCE RECORD GROUP, INQ Blow • PENETRATION - BLOW COUNT' Dense Brown, Grey And Black Silty Coarse To Fine SAND - Residual VVU„1 0 ,u eu :w au w tw 100 40 I 581.0 Very Dense Brown, Grey And Black Silty Coarse To Fine SAND _ 73 578.5 _ Dense Brown, Grey And Black Silty Coarse To Fine SAND 47 576.0 Partially Weathered Rock When Sampled Becomes Brown, Grey And Black Silty Coarse To Fine SAND 50/0.4 50/0.3 50/0.4 562.0 Partially Weathered Rock When Sampled Becomes Brown And Tan Silty Coarse To Fine SAND With Rock Fragments --------------------- 559.0 50/0.3 Boring Terminated Temporary Piezometer Installed From The Ground Surface To The Boring Termination Depth Of 25 Feet BORING .1ND 5'AMFLINGMET;rS ASr,M D-1586 CORE DRR.L.IIVG M 0 it AS1'M D-2113 'PENETRATION IS' TAF,NUMBER OF BLOWS OF A 140 LB. (63,5W HAMMER FALLING 30 IN. (76.2cm) RY'QUIRED'10 DRIVE A 1.4 IN. 6.3' ;0" PRESSURE ER'IESI' = WATER TABLE -24HIP I50I'i: ROCK CORE RECOVERY WAT'ERI'ABLE-IHR 4 I,OSB OF DRILLING WATER I• I C.'AVE-INDEP1Ti won WELGRrOFHAMMER PAGE 1Of1 MOM science for a changing world 2'2 470 FEET 35*00' U.S. DEPARTMENT OF THE INTERIOR #iThe National Mop WEDDINGTON QUADRANGLE U.S. GEOLOGICAL SURVEY Vi US Top NORTH CAROLINA-SOUTH CAROLINA 7.5-MINUTE SERIES SCALE 1:24 000 0.5 0 KILOMETERS 47'30" 47'30" I OGO 500 0 METERS 1DD0 2000 0.5 0 1 MILES 1000 0 1000 2000 30M 4000 5000 6000 7000 8000 9000 10000 FEET IRS 7. 35 1 CONTOUR INTERVAL 10 FEET NIIRTN 136 MILS 6 s ON NORTH AMERICAN VERTICAL DATUM OF 1988 dALIN MILS This map was produced to conform with the National Geospatlal Program US Tape, Product Standard, 2011 UTM GRID AND 2016 MAGNETIC NORTH A metadata file associated with this product Is draft version 0.6.19 9ursawas LacATNaI DECLINATION AT CENTER OF 5NW V.S. National Grid ROAD CLASSIFICATION Doom m S,W ID 1 Charlotte West Expressway Local Connector 1 2 3 2 Charlotte East Nu Secondary Hwy Local Road Mint Hitt Ramp 4WD — — — — — — 4 5 4 Fort Mill 5Matthews Grid tone oesignMion I. Interstate Route C3 US Route O state Route 6 Rock Hilt East i7s 6 7 8 7 Catawba NE 8 Waxhaw ADJOHING QUADRANGLES Produced by the United States Geological Survey North American Datum of 1983 (NAD83) World Geodetic System of 1984 (WGS84). Projection and 1 000-meter grid: Universal Transverse Mercator, Zone 17S 10 000-foot ticks: North Carolina Coordinate System of 1983, South Carolina Coordinate System of 1983 This map Is not a legal document. Boundaries may be generalized for this map scale. Private lands within government reservations may not be shown. Obtain permission before entering private lands. Imagery .............................................NAIP, October 2013 Roads ................................ U.S. Census Bureau, 2015 - 2016 Names..........................................................GNIS, 2016 Hydrography ....................National Hydrography Dataset, 2013 Contours............................National Elevation Dataset, 20D9 Boundaries ............ Multiple sources; see metadata file 1972 - 2016 Wetlands ......... FWS National Wetlands Inventory 1977 - 2014 Hydrologic Soil Group —Union County, North Carolina s (Reafiield Soil Map) B � w VICN 3 VrN 517470 517510 511t SIM 517m 3 Nap Scale: 1:1,910 ■pInted on A priest(&S' x 11')sheet N MEb� o a m +m 1m AFee o m 100 iao am Map pmedlan: Web Me ator CarrermardlnzMs: VVMN Fdgetla: t7lM Zo re 17N WGSM Uu.sDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey 517570 511710 511 3 Uhl. 1 o All W 1'WN I I 10/26/2017 Page 1 of 4 3Y 1'2"N Hydrologic Soil Group —Union County, North Carolina (Reafield Soil Map) MAP LEGEND Area of Interest (AOI) O Area of Interest(AOp Soils Soil Rating Polygons A ® AID B ® BID 0 C M CID D 0 Not rated or not available Soil Rating Lines y A ~ AID 0%0 B ~ BID .v C Ai CID y D • • Not rated or not available Soil Rating Points A AID B BID C CID D IO Not rated or not available Water Features -.. Streams and Canals Transportation µ� Rails N Interstate Highways 'y US Routes Major Roads Local Roads Background . Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Union County, North Carolina Survey Area Data: Version 16, Sep 20, 2016 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 14, 2015--Feb 8, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Natural Resources Web Soil Survey 10/26/2017 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group —Union County, North Carolina Reafeld Soil Map Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in Act Percent of AOI IrA Iredell loam, 0 to 3 percent slopes C/D 8.7 100.0% Totals for Area of Interest 8.7 100.0% Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff., None Specified OSDA Natural Resources Web Soil Survey 10/26/2017 ;illiO Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Union County, North Carolina Reafield Soil Map Tie -break Rule: Higher USDA Natural Resources Web Soil Survey 10/26/2017 Conservation Service National Cooperative Soil Survey Page 4 of 4