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HomeMy WebLinkAboutSW3190704_Report_(SHWT)_20200925GTA ASSOCIATES, INC. GEOTECHNICAL AND ENVIRONMENTAL CONSULTANTS A Practicing Geoprofessional Business Association Member Firm September 23, 2020 Coulston Enterprises, Inc. 8332 Regent Parkway Fort Mill, South Carolina 29715 Attn: Mr. Earl Coulston Re: Results of Seasonal High -Water Table Skyland Drive Townhomes S. Skyland Drive Mt. Pleasant, Cabarrus County, North Carolina Dear Mr. Coulston: As requested, GTA Associates, Inc. (GTA) visited the subject property on August 9, 2020 to install a temporary monitoring well in the proposed detention basin and evaluate the potential groundwater levels at the above reference project site. The field exploration consisted of performing one hand auger boring (P-1) to a depth of approximately 10 feet below the existing ground surface elevation in the proposed detention basin area. Once the hand auger boring was extended 10 feet, a slotted PVC standpipe was installed in the auger hole. The outside of the pipe was then backfilled with sand. The approximate location of the temporary PVC standpipe is shown on the attached "Temporary Monitoring Well Plan." Samples collected from the hand auger boring was submitted to GTA's laboratory for visual observations. Material descriptions are visual approximations in accordance with the Unified Soil Classification System (USCS). At the surface of P-1, native residual soils were encountered. The residual soils generally consist of stiff to very stiff lean clay (CL) in the upper 2 feet underlain by sandy silt (ML) in the upper 10 feet. Based on the "Grading Plan" prepared by American Engineering dated August 21, 2019, the ground surface elevation at P-1 is approximately Elevation 665 feet above mean sea level (MSL). Please note that the temporary monitoring well has not been surveyed. Please refer to Table 1 below for the results of the water level readings. 710 Peninsula Lane, Suite B, Charlotte, NC 28273 Phone: (704) 553-2300 Fax: (704) 553-2400 ♦ Abingdon, MD ♦ Baltimore, MD ♦ Laurel, MD ♦ Frederick, MD ♦ Waldorf, MD ♦ Sterling, VA ♦ Fredericksburg, VA ♦ Malvern, OH ♦ Somerset, NJ t NYC Metro ♦ New Castle, DE t Georgetown, DE ♦ York, PA ♦ Quakertown, PA ♦ Towanda, PA ♦ Charlotte, NC Us& us on the web at www.gtaeag.com Coulston Enterprise, Inc. Re: Skyland Drive Townhomes, Mt. Pleasant, N.C. September 23, 2020 TABLE 1: WATER LEVEL READINGS GROUND WATER WATER WATER DEPTH OF PVC SURFACE LEVEL LEVEL LEVEL LOCATION STANDPIPE ELEVATION READINGS READINGS READINGS (ft) ft 8-9-20 8-24-20 9-22-20 P-1 665 10 DRY DRY DRY Based on the results of our visual observations, groundwater was not encountered in the temporary PVC standpipe on the dates evaluated. In addition, there were no signs of mottling (discoloration of the soils) and no signs of a seasonal high-water mark at P-1. Please be advised that groundwater levels are expected to fluctuate with changes in precipitation, drainage, and other factors. Based on the results of the water level readings and our visual observations, groundwater was not encountered to a depth of Elevation 655 feet (MSL) on the dates evaluated. GTA Associates, Inc. appreciates the opportunity to be of assistance to you. If you have any questions regarding this report, please feel free to contact our office at (704) 553-2300. Sincerely, GTA ASSOCIATES, INC. ,,,,,� I; LcAGi�G John P. Wille, P.E. Vice President Attachments: 9-23-20 Temporary Monitoring Well Plan, Figure 1 2 �r r�nu iW 'Jrl GRAPHIC SCALE a ►wr ,Px S SKYLAN❑ DRIVE (S.R4 2657) SG' PUBLIC RIGHT OF WAY Cp8 67/%9i V1ClI4rTY MAP ww — — — — — — — — — — a=-sci wrr t boa — maro,w,�..r 4 .i3 n pe—_------ f._—_�--- rr-,,,ana _ t ! Ij I r 1! j r 1 I Jr I} d f � ! J f ♦ �� y V - r AwaFc9rR�u,gk y I r f J ! 1 i f r �, I y if �� J r • ! r 1r 4� I f I ; AC.r t ' !f � Jr fr ` /r r1 �� I•I ii 'I t 'S � � I Jr y1 1 IJr I' VV yyl 5 li yi I r J IV, ! 1 -- i1 11 1 1 } I I I q t + IF J fl 1 II S]E'i3�12"W !]S8? iTS% 535'#S' 3 W 4GZ9 - — - "—� h j 4 i. mr „xs srr Ar,,eA. eawrs ava3 .x�arse � . fir-, ,� � { J rL —vy` t Fa��GrrY S�YEO' M. d - ;S£dAGrSA EP��G v.A rtaeS,rS A9.Eu tO M'R.�L rA rR 8r ` ly/ --� _ I ! ] >y nwR�] 1�' a �ddP9FIdfVJ�1l myµ, 6c.w1 y Ai: RPnTT [7TI7��JE:r i r� SEAL 0249p1 `rOyNGriE� a