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Home My WebLink AboutSW6130203_Soils/Geotechnical Report_20240116 (2) HAL OWEN & ASSOCIATES, INC. SOIL & ENVIRONMENTAL SCIENTISTS P.O. Box 400, Lillington NC 27546-0400 Phone(910) 893-8743/Fax(910) 893-3594 www.halowensoil.com 11 May 2023 Jarrod Hilliard Hilliard Engineering PO Box 249 Sanford,NC 27331 Reference: Soil Scientist Investigation for Stormwater Management 1775 Buffalo Lake Road; PIN 9586-77-4522.000 Dear Mr. Hilliard, A site investigation has been conducted for the above referenced property, located on the eastern side of Buffalo Lake Road(SR 1115) in Harnett County, North Carolina. The purpose of this investigation was to provide a general characterization of the soils in the area proposed for a stormwater infiltration device, including a determination of the depth to evidence of a seasonal high-water table and estimation of the permeability of the various soil layers. In-situ hydraulic conductivity testing was conducted at the estimated basin depth. All soil characteristics were described in accordance with the USDA Field Book for Describing and Sampling Soils. This report represents my professional opinion as a Licensed Soil Scientist. SOIL PROFILE A hand-powered auger boring was advanced in the area proposed for the infiltration device (Figure 1). Soil morphological characteristics indicating a seasonal high water table(SHWT)were not observed within 124 inches below surface. Infiltration rates (permeability)are most limited to approximately 1.0 in/hr in the loam layer from 96 to 114 inches. A soil profile description was collected and is attached to this report. The remainder of the soil profile will likely demonstrate permeabilities greater than 4.0 in/hr. HYDRAULIC CONDUCTIVITY ASSESSMENT A hydraulic conductivity test was conducted using a Compact Constant Head Permeameter (CCHP),also known as an Amoozemeter,by using the shallow well pump-in technique as detailed in the user's manual. Hydraulic conductivity results can vary, even within similar soils, depending on the temperature and composition of the water used, climatic conditions, proximity of the test layer to the water table, and other factors. Therefore, the results from one boring may not be indicative of the entire area. Soil Science Investigations • Wetland Delineations,Permitting, and Consulting HAL OWEN & ASSOCIATES, INC. The hydraulic conductivity test was performed on 4 May 2023 at a depth of 261.5 cm below surface. The depth of the proposed infiltration basin is 244 cm (96 in) below ground surface, below which the soils were observed to have a friable loamy texture to 289.5 cm (114 in). A constant head of water was established within the bore hole with a depth of 22.5 cm. Readings were made of the rate of water flow from the meter until it appeared that steady state had been reached about 3.5 hours later. The Glover Solution was used to calculate the hydraulic conductivity,where Ksat=A* Q,A= {sinh-1 (H/r)- [(r/H)2+ 1]1/2+r/H}/(2IIH2),Q is the steady- state rate of water flow from the CCHP into the bore hole,H is the depth of water in the bore hole, and r is the radius of the bore hole. The field collection data sheet is attached to the end of this report. Depth of Auger Hole H r A Q Ksat in cm cm cm cm-2 cm3/day cm/day in/hr 103 261.5 22.5 3 0.000578 95760 55.35 0.91 I appreciate the opportunity to provide this service and trust that you will feel free to call on me again in the future. If you have any questions or need additional information,please contact me at your convenience. O SOIL s�� Sincerely tiN A s f f&k,- Hal OLicensedwen Soil Scientist 14 1102 PQ.O OF NOR1AAC Soil Science Investigations • Wetland Delineations,Permitting, and Consulting HAL OWEN & ASSOCIATES, INC. Soil Scientist Investigation For Stormwater Management �� 50IL sti 1775 Buffalo Lake Road; PIN 9586-77-4522.000 �a5 \, °Wt. \i> 11 May 2023 `4o x\P%• ' Figure 1 ;i i 4,t - .0 '9 i10f 1, OP avolklik Ksat Test#1 ZOMI105M.T V use:VACANT Z Soil Profile #1 - 1 - _.. _'llidII '- - — ' - �• ro'r — Ill 'r --_,,,',. i li I I '— I I I 4 •j . { Iwn io�e II �� I I ' 1 - •erFi ' I T I ' i' / +I+I-PI - —_ — —_ _v _ - v � J Soil Science Investigations • Wetland Delineations,Permitting, and Consulting HAL OWEN & ASSOCIATES, INC. SOIL PROFILE DESCRIPTIONS FOR STORMWATER MANAGEMENT DEVICES PROJECT NAME: Buffalo Lake Road PROPOSED FACILITY: infiltration basin LOCATION OF SITE: 1775 Buffalo Lake Road COUNTY: Harnett EVALUATED BY: Hal Owen,NCLSS and Britt Wilson DATE EVALUATED: 11 April 2023 EVALUATION METHOD:Auger Boring®, Pit❑ PROFILE: 1 HORIZON DEPTH CONSIS- PERMEABIL MATRIXMOTTLES TEXTURE STRUCTURE NOTES (IN) TENCE ITY(IN/HR) A 0-7 10YR 4/4 LS GR VFR 14.0 Cl 7-20 10YR 6/6 LS GR FR 14.0 C2 20-40 10YR 5/6 SL GR FR 8.0 C3 40-50 10YR 5/6 LS GR VFR 12.0 C4 50-58 7.5YR 5/6 LS GR VFR 12.0 C5 58-96 7.5YR 6/6 10YR 7/3 LS GR VFR 12.0 C6 96-114 7.5YR 5/8 L SBK FR 1.0 C7 114-124 7.5YR 5/8 10YR 6/4 LS GR VFR 14.0 AWT NA SHWT >124" SLOPE 1% DRAINAGE SOIL SERIES Lakeland VEGETATION grasses and weeds,few trees COMMENTS: Soil Science Investigations • Wetland Delineations,Permitting, and Consulting HAL OWEN & ASSOCIATES, INC. LEGEND OF ABBREVIATIONS FOR SOIL PROFILE DESCRIPTIONS TEXTURE MOIST CONSISTENCE S - Sand L - Loose LS - Loamy Sand VFR -Very Friable SL - Sandy Loam FR -Friable L - Loam FI -Firm SCL - Sandy Clay Loam VFI -Very Firm CL - Clay Loam EFI - Extremely Firm SiL - Silt Loam Si - Silt SiCL- Silt Clay Loam SC - Sandy Clay AWT—Apparent Water Table C - Clay SHWT—Seasonal High Water Table SiC - Silty Clay SLWT— Seasonal Low Water Table O - Organic MOTTLES f —few 1 - fine F - Faint c —common 2 -medium D - Distinct m —many 3 - coarse P - Prominent STRUCTURE 0 - structureless VF - very fine G - Single Grain 1 - weak F - fine M -Massive 2 - moderate M - medium CR - Crumb 3 - strong C - coarse GR - Granular VC -very coarse SBK - Subangular Blocky ABK -Angular Blocky PL -Platy PR -Prismatic Soil Science Investigations • Wetland Delineations,Permitting, and Consulting HAL OWEN & ASSOCIATES, INC. Ksat DATA SHEET Measurement#: 1 _ Date: 5/4/2023 Investigator: Kris Newcomb,Jocelyn Prouxl Location: stormwater basin Weather-- Condition: Mostly Sunny, slight breeze Temp: 70 deg F Water— Source: Harnett County tap Temp: 72 deg F Soil Horizon: B6 Layer Depth and Thickness: 96"-114" Slope: 1% calculate constant-head tube setting: cm Constant Head Tubes Air Tubes 1 a af, H , Hole Depth: 261.5 Water40— 4/ 1 Level T Distance between reference level + 12.0 y � — and top of hole [-12cm on flat sites] • • Main Distance from bottom of hole Reservoir = 273.5 • to reference level(D) • Flow Measuring Desired depth of water(H) 5� Reservoir o H1 ' 10 crn - • • [ > 15cm] Constant-head tube setting (HI) = 255.5 • Reference Level Start Saturation: 1:15PM Auger hole\ d Measured (Actual) d=H1(+50 or 100 or 150) water level in hole: 22.5 cm Constant Water Level H Hole radius (r): 3 cm Ksat=AXQ Use Table 2 to determine A= 0.000578 cm-2 Q from other side = 95760 cm3/day Ksat= 55.35 cm/day = 0.91 in/hr Soil Science Investigations • Wetland Delineations,Permitting, and Consulting HAL OWEN & ASSOCIATES, INC. H Clock Reservoir Change Change Lcm Q Q Time Reading in time in water Amin (multiply by level C F') (multiply by 1440 min/day) cm h : min cm min cm cm/min cm3/min cm3/day 3:41 29 3 3.6 1.2 136.5 196560 3:43 26.2 3 2.8 0.9333 98.0 141120 24.5 3:47 19.5 3 6.7 2.23 234.5 337680 3:50 16.7 3 2.8 0.9333 98.0 141120 24.5 3:53 12.9 3 3.8 1.2667 133.0 191520 3:56 8 3 4.9 1.6333 171.5 246960 3:59 4 3 4 1.333 140.0 201600 Refill 4:07 46.4 X X X X X 4:10 45.4 3 1 0.3333 35.0 50400 4:13 43.5 3 1.9 0.6333 66.5 95760 22.5 4:16 42.3 3 1.2 0.4000 42.0 60480 4:19 40.5 3 1.8 0.6000 63.0 90720 4:22 38.5 3 2 0.6667 70.0 100800 4:25 36.5 3 2 0.6667 70.0 100800 4:28 34.6 3 1.9 0.6333 66.5 95760 4:31 32.7 3 1.9 0.6333 66.5 95760 22.5 4:34 30.8 3 1.9 0.6333 66.5 95760 4:37 28.8 3 2 0.6667 70.0 100800 1C.F.(Conversion Factor): 1-ON=20 cm2 , 2-ON=105 cm2 Average of last few measurements: 95760 cm3/day Soil Science Investigations • Wetland Delineations,Permitting, and Consulting