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Home My WebLink AboutSL10322-6 250 Tank Farm Rd Infiltration Testing ReportGEOV11111ha., SC:--)LIJ I IC-3IV1_Z_ DATE: December 20, 2023 PROJECT NUMBER: SL10322-6 CLIENT: Tank Farm Road, LLC 7036 Valley Greens Circle Carmel, California, 93923 Project name: Parcels 10 and 11 250 Tank Farm Road APN: 053-251-083, -084, and -085 San Luis Obispo California 220 High Street San Luis Obispo CA 93401 805.543.8539 1021 Tama Lane, Suite 105 Santa Maria, CA 93455 805.614.6? 201 S. Milpas Street, Suite 103 Santa Barbara, CA 93103 805.966.2200 info4geosolutions. net sbinfo4*ge0so1utions. net INFILTRATION TESTING REPORT INTRODUCTION GeoSolutions, Inc. performed infiltration — t testing using the shallow quick test methodology on n November 10, 2023 for the proposed development of mini - storage unit facility to be located at Parcels 10 and ,.,. 11, 250 Tank Farm Road, APN: 053-251-083, -084, and -085, San Luis Obispo County, California. TA.`:;; :ARAI p See Figure 1: Site Location Map for the general location of the project area. The property 5048A-V QC will hereafter be referred to as the "Site". Infiltration testing was performed for the design Q of storm water control measures at the Site. 0 1000 fti GISsurfer v3 0 Cursor 250 Tank Farm Road is mappingsupport.com Center 35246846 -120 666146 located at 35.2468 degrees north latitude and Figure 1: Site Location Map -120.6661 degrees east longitude at a general elevation of 120 feet above mean sea level. The property is approximately rectangular in shape and 3.76 acres in size. The nearest intersection is where Sueldo Street intersects Vanguard Way approximately 100 feet to the west of the property. The property is relatively flat with a general elevation of about 120 feet above sea level. Surface drainage follows the topography offsite to Tank Farm Road. FIELD EXPLUKA I w, Four, six-inch diameter infiltration test borings were drilled on November 7, 2023 to a maximum depth of 10 feet below ground surface (bgs) at the approximate locations indicated on Figure 2: Infiltration Test Locations. Three-inch diameter perforated PVC pipe was placed in the infiltration test borings and annular space was filled with clean pea gravel. Groundwater and/or impermeable strata were not encountered in any of the infiltration test borings, although groundwater was encountered during the field investigation for the soils engineering report, at depths of 11.0 to 12.0 feet below ground surface. The following field soil classifications for the borings are in accordance with the Unified Soils Classification System (USCS). The material at the Site generally consisted of very dark grayish brown sandy lean CLAY (CL) with gravels encountered in a dry to moist condition to approximately 6.0 to 7.0 feet bgs. The sub -surface materials consisted of grayish brown clayey SAND (SC) with gravels encountered in a slightly moist to moist condition. 250 Tank Farm Road December 20. 2023 Proiect SU 0322-6 INFILTRATION TESTING Prior to infiltration testing, each infiltration test boring was presoaked to a stabilized percolation rate. Infiltration testing consisted of maintaining a constant head of for 30 minutes, then measuring the depth to the water immediately following. Measurements were then performed for a determined period of time of 30 minutes. Testing was terminated after an elapsed time of 240 minutes. The infiltration rates (in inches per hour) were calculated by dividing the time period of the last reading obtained by the recorded water elevation drop. The infiltration test results for the Site are attached. Table 1: Infiltration Test Results Figure 2: Infiltration Test Locations est ocation Depth ( Rate (inches/hour) November 10, 2023 1-1 10 0.48 I-2 5 0.72 1-3 2 0.96 I-4 10 0.48 CONCLUSIONS The infiltration test results indicate that infiltration rates of the surface materials may be categorized for hydrologic purposes utilizing the Hydrologic Soil Group (HSG)' classification of group B for soils in the upper 5 feet of the Site and a classification of group C . This classification is based on the site soil profile consisting primarily of sandy soils with 10 to 40 percent clay content, a low to moderate swelling potential, and water transmission rates between 1.42 and 0.06 inches per hour. These test results correspond to moderate infiltration rates and moderate runoff potential. In addition to the infiltration testing, soil samples were obtained during the field investigation for the soils engineering report and laboratory tested for particle size distribution. The soils were classified as sandy CLAY (CL) with 65% clay fines and clayey SAND (SC) with 41.9% clay fines. Based on the clay content of the site soils, the soils classify as Group D, which have high runoff potential and restricted to very restricted water movement through the soil. It is our opinion that for long duration saturated conditions, the soil will behave as a Group D with infiltration rates as low as 0.06 inches per hour. GEO Y 250 Tank Farm Road December 20. 2023 Proiect SL10322-6 It is recommended that stormwater basins and storm chambers be located a horizontal distance of at least 10 feet away from building pad areas. The potential impact of stormwater migration during extended periods of rainfall from basins and storm chambers into adjacent utility trenches should be considered, as settlement of saturated trench backfill materials can occur. "(Part 630, Hydrology, National Engineering Handbook, 2007) LIMITATIONS Changes in the location of the proposed storm water control measures will render our findings invalid unless our staff reviews such changes. Subsurface exploration of any site is not necessarily confined to selected location and conditions may, and often do, vary between and around these locations. If varied conditions are encountered during installation, additional exploration and testing may be required. If the installer should discover field conditions that are different from those described in this letter, GeoSolutions, Inc. should be notified immediately for further evaluation. Thank you for the opportunity to have been of service for Infiltration testing and reporting. If you have any questions or require additional assistance, please feel free to contact the undersigned at (805) 543-8539. Since C,po� m Krai er, PE �k Princi I 1►�/�L �yQ q�FOF CR1-�F�� Attachments: Infiltration Boring Logs Infiltration Test Results SASL10000-SL10499\SL10322-6 -Parcels 10 and 11, 250 Tank FarmMeissner\Engineedng1SL10322-6 250 Tank Farm Road Infiltration Report.doc GEO� 220 High Street, San Luis Obispo, CA 93401 INFILTRATION Phone:805-543-8539 1021 Tama Lane, Ste 105, Santa Maria, CA 93455 LOG EO Phone:805-614-6333 BORING NO. I-1 +,� 201 S. Milpas St, Ste 103, Santa Barbara, CA 93103 Phone: 805-966-2200 JOB NO. SL10322-6 PROJECT INFORMATION DRILLING INFORMATION PROJECT: 250 Tank Farm Road DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 6 Inches DATE DRILLED: November7, 2023 SAMPLING METHOD: N/A LOGGED BY: D. Wordeman APPROX. ELEVATION: Not Recorded Depth of Groundwater: Not Encountered Boring Terminated At: 10 Feet 1 of 1 ANNULAR WELL CASING > MATERIAL MATERIAL WELL = w p `D o � J U � SOIL DESCRIPTION DESCRIPTION DESCRIPTION CROSS-SECTION CL SC 10 11 12 13 14 15 16 17 18 19 on �N�\ N N N �N/N N N N �N�N N N N /NiN N N N iNiN N N N /NiN N N N /NiNNNN /N/N N N N /NiN N N N iN/N N N N iNiNNNN /N/N N N N iN/NNNN iNiNNNN iNiNNNN iNiNNNN %/N/N/N/N %/N/N/N/N iNiN N N N %/N/N/N/N %/N/N N �N�N N N \ %/N/N N �N�\ N N N �N�NNNN ix x z /N/ /NiNNNN /NiN N N N /z /. / / N/ /NiNNNN /N/NNNN /NiN N N N /NiNNNN /N/N N N N /N/N N N N /N/NNNN /.xx// /NiN N N N O/NN N N N /NON N N N /NiN/ / / /NxN/ / / /NiNz / / /'/NON/Nx 220 High Street, San Luis Obispo, CA 93401 INFILTRATION Phone:805-543-8539 GEo. 1021 Tama Lane, Ste 105, Santa Maria, CA 93455 LOG Phone: 805-614-6333 BORING NO. 1-2 201 S. Milpas St, Ste 103, Santa Barbara, CA 93103 Phone: 805-966-2200 JOB NO. SL10322-6 PROJECT INFORMATION DRILLING INFORMATION PROJECT: 250 Tank Farm Road DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 6 Inches DATE DRILLED: November 7, 2023 SAMPLING METHOD: N/A LOGGED BY: D. Wordeman APPROX. ELEVATION: Not Recorded Depth of Groundwater: Not Encountered Boring Terminated At: 5 Feet 1 of 1 ANNULAR WELL CASING r MATERIAL MATERIAL WELL SOIL DESCRIPTION DESCRIPTION DESCRIPTION CROSS-SECTION _ W 0 ~ 0 J � 1 ■ CL 6- 10 11 12 13 14 15 16 17 18 19 on 220 High Street, San Luis Obispo, CA 93401 INFILTRATION Phone: 805-543-8539 G 1021 Tama Lane, Ste 105, Santa Maria, CA 93455 I± LOG E 0, Phone: 805-614-6333 BORING NO. 1-3 201 S. Milpas St, Ste 103, Santa Barbara, CA 93103 Phone: 805-966-2200 JOB NO. SL10322-6 PROJECT INFORMATION DRIWNG INFORMATION PROJECT: 250 Tank Farm Road DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 6 Inches DATE DRILLED: November 7, 2023 SAMPLING METHOD: N/A LOGGED BY: D. Wordeman APPROX. ELEVATION: Not Recorded Depth of Groundwater: Not Encountered Boring Terminated At: 2 Feet 1 of 1 ANNULAR WELL CASING y MATERIAL MATERIAL WELL C' o SOIL DESCRIPTION DESCRIPTION DESCRIPTION CROSS-SECTION _ p J (N U � CL 10 11 12 13 14 15 16 17 18 19 on 220 High Street, San Luis Obispo, CA 93401 INFILTRATION Phone:805-543-8539 GE.o...-, 1021 Tama Lane, Ste 105, Santa Maria, CA 93455 LOG Phone: 805-614-6333 BORING NO. 1-4 201 S. Milpas St, Ste 103, Santa Barbara, CA 93103 Phone: 805-966-2200 JOB NO. SL10322-6 PROJECT INFORMATION DRILLING INFORMATION PROJECT: 250 Tank Farm Road DRILL RIG: Mobile B-24 DRILLING LOCATION: See Figure 2, Site Plan HOLE DIAMETER: 6 Inches DATE DRILLED: November7, 2023 SAMPLING METHOD: N/A LOGGED BY: D. Wordeman APPROX. ELEVATION: Not Recorded Depth of Groundwater: Not Encountered Boring Terminated At: 10 Feet 1 of 1 ANNULAR WELL CASING > MATERIAL MATERIAL WELL CD c SOIL DESCRIPTION DESCRIPTION DESCRIPTION CROSS-SECTION = a w p = M U � CL SC 9- 10- 11- 12- 13- 14- 15- 16- 17- 18- 19— on rNrN N N N iNiN N N N rNiN N N N rNiN N N N rNiN N N N rNiN N N N rNiN N N N iNiN N N N r�i�/ / / ri NN N NN rNiN N N N rNiN N N N rNrNrN N irrrr, rNrNr.NrNrN rNrN N N N rNrN N N N rNiN N N N rNrN N N N rNrN N N N rNrN N N N rNrN N N N rNrN N N N rNiN N N N rNrN N N N rNrN N N N rN\NNX r�/N/. r� rrrrr GeoSolutions, Inc. INFILTRATION TEST RESULTS (805) 543-8539 (805) 614-6333 Project: 250 TANK FARM Project No.: SL10322-6 Infiltration Test: 1-1 Test Hole Diameter: 6 Inches Date Drilled: 11/7/2023 Test Hole Depth: 10.0 Feet Date Tested: 11/10/2023 Test Duration: 4.0 Hours Technician: -- Test Hole Type: Standard 2" PVC TEST METHODOLOGY: CONSTANT HEAD STANDARD Time of Constant Head: Constant Head Utilized for Test: Gross Volume of Test Boring, Bottom to Constant Head: Volume of Gravel in Test Boring: Net Volume of Test Boring, Bottom to Constant Head: Initial Meter Reading: Meter Reading at 30 Minutes: Volume Required to Maintain Head for 30 Minutes: FALLING HEAD 30 Minutes 7.94 Feet 1.56 Cubic Feet 1.39 Cubic Feet 0.17 Cubic Feet Gallons Cubic Feet A - 5 0.67 TIME ELAPSED TIME* (Minutes) READING (Feet) INCREMENTAL FALL (Feet) INFILTRATION RATE (Minutes/Inch) INFILTRATION RATE (inches/Hour) t':30 AM 0 7.9d - -- - 8:00 AM 30 8.0E 0.12 20.83 2.88 8:30 AM 60 8.10 0.04 62.50 0.96 9:00 AM 1 90 8.14 0.04 62.50 0.96 9:30 /, 120 8.18 0.04 62.50 0.96 10:00 AM 150 8.21 0.03 83.33 0.72 10:30 AM ' °^ 8.24 0.03 83.33 0.72 11:00 AM 8.27 0.03 83.33 0.72 11:30 AM 240 8.29 0.02 125.00 0.48 INFILTRATION RATE (Inches/Hour) 1 0.48 of San Luis Obispo, Post Construction Requirements Handbook (Version 1.1 - March 20 Page of 4 I GeoSolutions, Inc. INFILTRATION TEST RESULTS (805) 543-8539 I (805)614-6333 Infiltration Test: 1-2 Test Hole Diameter: 6 Inches Date Drilled: 11/7/2023 Test Hole Depth: 5.0 Feet Date Tested: 11/10/2023 Test Duration: 4.0 Hours Technician: r)B Test Hole Type: Standard 2" PVC TEST METHODOLOGY: CONSTANT HEAD STANDARD Time of Constant Head: Constant Head Utilized for Test: Gross Volume of Test Boring, Bottom to Constant Head: Volume of Gravel in Test Boring: Net Volume of Test Boring, Bottom to Constant Head: Initial Meter Reading: Meter Reading at 30 Minutes: Volume Required to Maintain Head for 30 Minutes: FALLING HEAD 30 Minutes Feet 0.43 Cubic Feet 0.38 Cubic Feet 0.05 Cubic Feet Gallons Cubic Feet 4 0.53 TIME ELAPSED TIME* (Minutes_) READING (Feet) I INCREMENTAL FALL (Feet) INFILTRATION RATE (Minuteslinch) INFILTRATION RATE (Inches/Hour) :32 AM 0 z.20 - - - 8:02 AM 30 2.44 0.24 10.42 5.76 8:32 AM 60 2.56 0.12 20.83 2.88 9:02 AM 90 2.68 0.12 20.83 2.88 9:32 AM 120 2.79 0.11 22.73 2.64 10:02 AM 150 2.88 0.09 27.78 2.16 10:32 AM 180 2.93 0.05 50.00 1.20 11:02 AM 210 2.97 0.04 62.50 0.96 11:32 AM 240 3.00 0.03 83.33 0.72 INFILTRATION RATE (inches/Hour) 0.72 of San Luis Obispo, Post Construction Requirements Handbook (Version 1.1 - March 201 Page of 4 I GeoSolutions, Inc. INFILTRATION TEST RESULTS (805) 543-8539 I (805)614-6333 Project: P TANK FARM Project No.: SL10322 Infiltration Test: 1-3 Test Hole Diameter: b Inches Date Drilled: 11/7/2023 Test Hole Depth: 2.0 Feet Date Tested: 11/10/2023 Test Duration: 4.0 Hours Technician: in Test Hole Type: Standard 2" PVC TEST METHODOLOGY: CONSTANT HEAD STANDARD Time of Constant Head: 30 Minutes Constant Head Utilized for Test: Feet Gross Volume of Test Boring, Bottom to Constant Head: 0.17 Cubic Feet Volume of Gravel in Test Boring: 0.15 Cubic.Feet Net Volume of Test Boring, Bottom to Constant Head: 0.02 Cubic Feet Gallons Cubic Feet Initial Meter Reading: - Meter Reading at 30 Minutes: - Volume Required to Maintain Head for 30 Minutes: 2 0.27 FALLING HEAD TIME ELAPSED TIME" (Minutes) READING (Feet) INCREMENTAL FALL (Feet) INFILTRATION RATE (Minutes/Inch) INFILTRATION RATE (Inches/Hour) i. 0 - -- - 8:Os Ann 30 0.08 31.25 1.92 8:33 AM 60 0.11 22.73 2.64 9:03 AM 90 0.09 27.78 2.16 9:33 AM 120 0.07 35.71 1.68 10:03AM 150 0.06 41.67 1.44 10:33 AM 180 1.31 0.04 62.50 0.96 11:03 AM 210 1.35 0.04 62.50 0.96 11:33 AM 240 1.39 0.04 62.50 0.96 INFILTRATION RATE (inches/Hour) 0.96 of San Luis Obispo, Post Construction Requirements Handbook (Version 1.1 - March 201 Page of 4 GeoSolutions, Inc. INFILTRATION TEST RESULTS (805) 543-8539 (805) 614-6333 Project: 250 TANK FARM Project No.: SL10322-6 Infiltration Test: 1-4 Test Hole Diameter: 6 Inches Date Drilled: 11/7/2023 Test Hole Depth: 10.0 Feet Date Tested: 11/10/2023 Test Duration: 4.0 Hours Technician: DB Test Hole Type: Standard 2" PVC TEST METHODOLOGY: STANDARI CONSTANT HEAD Time of Constant Head: Constant Head Utilized for Test: Gross Volume of Test Boring, Bottom to Constant Head: Volume of Gravel in Test Boring: Net Volume of Test Boring, Bottom to Constant Head: Initial Meter Reading: Meter Reading at 30 Minutes: Volume Required to Maintain Head for 30 Minutes: FALLING HEAD 30 Minutes 7.72 Feet 1.52 Cubic Feet 1.35 Cubic Feet 0.17 Cubic Feet Gallons Cubic Feet 0.67 TIME ELAPSED TIME* (Minutes) READING (Feet) INCREMENTAL FALL (Feet) INFILTRATION RATE (Minutes/inch) INFILTRATION RATE (inches/Hour) 7:31 AM 0 - - - 8:01 AM %J 0.17 14.71 4.08 8:31 AM 60 0.13 19.23 3.12 9:01 AM 1 90 0.08 31.25 1.92 9:31 AM 120 0.05 50.00 1.20 '1:01 AM 150 0.04 62.50 0.96 431 AM 180 0.02 125.00 0.48 11:01 AM 210 0.02 125.00 0.48 1131 AM 240 0.02 125.00 0.48 INFILTRATION RATE (inches/Hour) 0.48 lReference: County of San Luis Obispo, Post Construction Requirements Handbook (Version 1.1 - March